iPRE-SCHOOL HEARING SCREENING IN A SELECTED SCHOOL IN
KORLE BU, GHANA
DANIEL AVOYEM TUMPI
(10374001)
A DISSERTATION SUBMITTED TO THE DEPARTMENT OF
AUDIOLOGY, SPEECH AND LANGUAGE TEHRAPY,
SCHOOL OF BIOMEDICAL AND ALLIED HEALTH SCIENCES,
UNIVERSITY OF GHANA
IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE
AWARD OF MASTER OF SCIENCE DEGREE IN AUDIOLOGY
JULY 2013
University of Ghana                              http://ugspace.ug.edu.gh
iDECLARATION
I, DANIEL AVOYEM TUMPI hereby declare that this dissertation which is being submitted in
partial fulfilment of the requirements for the degree of MSc. in Audiology is the result of my
own independent research project or investigation and that, except where otherwise other sources
are acknowledged with explicit references and are included in the reference list, this work has
not previously been accepted in substance for any degree and neither is it being concurrently
submitted in candidature for any degree
I hereby give permission for the Department of Audiology, Speech and Language Therapy to
disseminate the dissertation in any appropriate format. Authorship in such circumstances shall be
jointly held between me as the first author and my supervisors as subsequent authors.
Signed ……………………………………………………… Date ………...………...
DANIEL AVOYEM TUMPI (10374001)
Signed ……………………………………………………… Date …………....……...
Dr. SAMUEL ANIM-SAMPONG
(Principal Supervisor)
Signed ……………………………………………………… Date ……....…………...
PROF. EMMANUEL DORNU KITCHER
(Secondary Supervisor)
Signed ……………………………………………………… Date ……....…………...
Head of Department
University of Ghana                              http://ugspace.ug.edu.gh
ii
DEDICATION
I dedicate this work to my beloved wife Rose Tumpi and my four lovely daughters especially the
twins, Ruth and Ruthann Tumpi
University of Ghana                              http://ugspace.ug.edu.gh
iii
ACKNOWLEDGEMENT
The pleasure is mine to express my profound gratitude to God almighty for giving me the
strength, energy and grace to accomplish this work. I also wish to acknowledge the efforts of my
supervisors Dr. Samuel Anim-Sampong and Prof. Emmanuel Dornu Kitcher for their valuable
contributions to my work via suggestions, corrections, guidance and support.
I will also like to thank Dr. Neal Boafo, a Clinical Audiologist and Lecturer in the Department
for his technical and professional support in realizing the goals of this research dissertation. I am
indebted to my fellow colleagues of the Hearing Assessment Centre of Korle Bu Teaching
Hospital - Mrs. Grace Ocansey, Mrs. Jemima Fynn, Mrs. Florence Mensah, Mrs. Josephine
Decker Aryee, Mrs. Rejoice Acquah, and Mr. George Teye for their interest and support. The
moral and technical support of Messrs. Sesi Collins Akotey, Ronald N. Adjekum and Anthony
Azaglo, all former students of the Department is also acknowledged.
Finally, the assistance accorded me by my dear daughter, Miss Mary Tumpi (MSc Audiology
candidate) throughout this work is also acknowledged.
University of Ghana                              http://ugspace.ug.edu.gh
iv
TABLE OF CONTENTS
DECLARATION………………………………………………………………………………..i
DEDICATION……………………………………………………………………………….…ii
ACKNOWLEDGEMENT……………………………………………………………………...iii
LIST OF TABLES……………………………………………………………………………...vii
LIST OF FIGURES…………………………………………………………………………….viii
LIST OF ABBREVIATIONS…………………………………………………………………..ix
ABSTRACT…………………………………………………………………………………….x
CHAPTER ONE: INTRODUCTION………………………………………………………..1
1.1 BACKGROUND………………………………………………………………………..1
1.2 PROBLEMSTATEMENT………………………………………………………………2
1.3 AIM……………………………………………………………………………………...3
1.4 OBJECTIVES …………………………………………………………………………...3
1.5 RESEARCH QUESTIONS……………………………………………….……………..4
1.6 SIGNIFICANCE OF THE STUDY..................................................................................4
CHAPTER TWO: LITERATURE REVIEW………………………………………….….…5
2.1 INTRODUCTION…………………………………………………………….…………5
2.2 SCREENING FOR HEARING LOSS IN GHANA…………………………………….5
2.3 PREVALENCE OF HEARING LOSS AMONG PRE-SCHOOL CHILDREN….…….6
2.4 IMPLICATIONS OF HEARING LOSS IN CHILDREN……………………………....8
2.4.1 Audiologic Implications…………………………………………………….…...9
2.4.2 Communication Effects……………………………………………….………....9
2.4.3 Academic Effects…………………………………………………………...……9
2.8 Social Effects…....................................................................................................10
2.5 SIGNIFICANCE OF EARLY DETECTION…………………………………….…….10
University of Ghana                              http://ugspace.ug.edu.gh
v2.6 ELEMENTS OF AUDIOMETRY……………………………………………………..11
2.61 Test Environment……………………………………………………………….11
2.6.2 Controlling Test Room…………………………………………………….……12
2.63 Testing Protocol………………………………………………………………...12
2.7 PHYSICAL EXAMINATION OF THE EAR……………………………………..…..13
CHAPTER THREE: MATERIALS AND METHODS ………………………………….14
3.1 INTRODUCTION………………………………………………………………….…..14
3.2 RESEARCH DESIGN…………………………………………………………….....…14
3.3 STUDY SITE…………………………………………………………………………..14
3.4 POPULATION…………………………………………………………….…………...15
3.5 SAMPLE AND SAMPLING TECHNIQUES…………………………..………….….15
3.6 INCLUSION AND EXCLUSION CRITERIA…………………………...……….…...15
3.6.1 Inclusion Criteria……………………………………………………………….15
3.6.2 Exclusion Criteria………………………………………………….……..…….15
3.7 INSTRUMENTATION………………………………………………..……………….15
3.8 AUDIOLOGIC SCREENING TEST…………………………….…...………………..16
3.9 PROTOCOL FOR TESTING AND DATA COLLECTION…………………………..17
3.10 ETHICAL CONSIDERATION…………………………………………..…………....18
3.11 DATA ANALYSIS……………………………………………………..……………...18
CHAPTER FOUR: RESULTS………………………………………………..……………..19
4.1 INTRODUCTION…………………………………………………………..………….19
4.2 DESCRIPTIVE STATISTICS……………………………………………….………...19
4.2.1 Demographic Characteristics…………………………………………………..19
4.2.2 Otoscopic Examination and Hearing Screening Results…………….…………20
4.3 INFERENTIAL STATISTICS………………………………………………..………..24
University of Ghana                              http://ugspace.ug.edu.gh
vi
4.3.1 Association between Otoscopy and Age……………………… ………………21
4.3.2 Association between Pure tone Audiometry and Age ………… ……………. 22
4.3.3 Association between Pure tone Audiometry and Gender ……… …………….28
CHAPTER FIVE: DISCUSSIONS…………………………………………… …………... 32
5.1 INTRODUCTION………………………………………………………… ………….32
5.2 DEMOGRAPHICS………………………………………………………… …………32
5.3 OTOSCOPIC EXAMINATION……………………………………………… ………32
5.3.1 Outcome of Otoscopic Examination…………………………………… ……..32
5.3.2 Pure tone Screening Audiometry………………………………………………33
5.4 OUTCOME OF HEARING SCREENING……………………………………… …..33
CHAPTER SIX: CONCLUSIONS AND RECOMMENDATIONS ……………… …35
6.1 INTRODUCTION…………………………………………………………………… .35
6.2 SUMMARY OF STUDY............................................................................................ ..35
6.3 CONCLUSION…………………………………………………………………… ….36
6.4 RECOMMENDATIONS…………………………………………………………… ..37
6.5 LIMITATION OF THE STUDY……………………………………………..…… …37
REFERENCES……………………………………………………………………………… ..38
University of Ghana                              http://ugspace.ug.edu.gh
vii
LIST OF TABLES
Table 3.1: Technical specifications of audiometers …………………..……………………….. 16
Table 4.1: Age and gender distributions………………………………………………………...19
Table 4.2: Distribution of hearing screening results at test frequencies……………………..… 20
Table 4.3: Prevalence of hearing loss at test frequencies for right and left ears ……………….21
Table4.4: Association between otoscopy and age for right and left ears ……………………....22
Table 4.5: Association between pure tone audiometry and age for both ears at 500Hz…..……23
Table 4.6: Association between pure tone audiometry and age for both ears at 1000Hz……....24
Table 4.7: Association between pure tone audiometry and age for both ears at 2000Hz………25
Table 4.8: Association between pure tone audiometry at 4000Hz and age for both ears ……....26
Table 4.9: Association between pure tone audiometry at 6000Hz and age for both ears……….26
Table 4.10: Association between pure tone audiometry and gender for both ears at 500Hz…....28
Table 4.11: Association between pure tone audiometry and gender for both ears at 1000Hz .....29
Table 4.12: Association between pure tone audiometry and gender for both ears at 2000Hz..…30
Table 4.13: Association between pure tone audiometry and gender for both ears at 4000Hz…..30
Table 4.14: Association between gender at 6000Hz……………………………………………..31
University of Ghana                              http://ugspace.ug.edu.gh
viii
LIST OF FIGURES
Figure 3.1: Schematic flowchart of pure tone audiometry……………......................................16
Figure 4.1: Frequency variation with pass rate for different age groups……………………….27
Figure 4.2: Frequency variation with referral rate for different age groups ………………….28
University of Ghana                              http://ugspace.ug.edu.gh
ix
LIST OF ABBREVIATIONS
ABR Auditory Brain Response
AN Auditory Neuropathy
APD Auditory Processing Disorder
ASHA American Speech Language and Hearing Association
CORs Conditioned Oriented Responses
dB Decibels
EOAE Evoked Otoacoustic Emissions
EPRC Ethics and Protocol Review Committee
KBTH Korle Bu Teaching Hospital
LiNKS Lilliput Nursery and Kindergarten School
NIH National Institute of Health
OAE Otoacoustic Emissions
OHC Outer Hair Cell
OKAT Oklahoma Auditory Taskforce
OME Otitis Media
SBAHS School of Allied Health Sciences
UNICEF United Nations Children’s Educational Fund
VRA Visual Reinforced Audiometry
University of Ghana                              http://ugspace.ug.edu.gh
xABSTRACT
Background: Hearing impairment has detrimental effects on the linguistic and educational
development of children. In developing countries routine screening programmes for hearing
impairment is minimal.
Aim: The aim of the study was to screen pre-school pupils for hearing loss and related ear
pathologies and determine the prevalence of hearing loss at test frequencies for purposes of early
management and intervention.
Methods: Across sectional study design was adopted to purposively sample and screen 150 pre-
school pupils aged 3 – 5 years of a nursery school via otoscopic examinations and pure tone
screening audiometry. The audiological screening was conducted in a quiet environment with a
30dBHL and 25dBHL pass/refer criteria at 500 Hz and 1 kHz to 6 kHz respectively.
Results: The highest prevalence of hearing loss were registered at 500 Hz (14%) and 6000 Hz
(9%), while a prevalence of 6% -7% was recorded for test frequencies of 1000 Hz – 4000 Hz.
Statistical analysis via chi-square tests established no significant association between pure tone
hearing screening and age and gender of the pre-school children for both ears at different test
frequencies (500 Hz – 6000 Hz).
Conclusions: The results from the study affirmed that hearing screening was very necessary at
the pre-school level and provides a baseline for building a more comprehensive pre-school
hearing screening protocol for early identification and detection of hearing loss
Keywords: Pre-school pupils, pure tone audiometry, otoscopic examination, hearing loss,
prevalence.
University of Ghana                              http://ugspace.ug.edu.gh
1CHAPTER ONE
INTRODUCTION
1.1   BACKGROUND
According to the British Association of Otolaryngology and British Society of Audiology
(1983), hearing loss is defined as a loss in hearing sensitivity between test frequencies of 1000
Hz - 4000 Hz. Hearing loss is the most common developmental disorder identifiable at birth
(White, 1997) and its prevalence increases throughout school‐age due to additions of late‐onset,
late identification and acquired hearing loss. The primary justification for early identification of
hearing impairment among pre-school children relates to its impact on speech and language
acquisition, cognitive achievements and social and emotional development. Reduced hearing
acuity during infancy and early childhood, most especially during pre-school stages interferes
with the development of speech and language skills. This is due to the likelihood that the child
may not receive adequate auditory and linguistic stimulation required for speech and language
learning as well as social and emotional development (National Institute of Health, 1993).
Childhood hearing impairment has a detrimental effect on linguistic and educational
development. Data on early childhood (0-5 years) hearing impairment in developing countries is
scarce or of limited value due to the lack of infant hearing screening programs (Bolajoko, 2008).
Available studies are predominantly among school-aged children in mainstream schools. In
developed countries, the incidence of congenital hearing loss is 0.004% in live births (White,
2004). In another study, of the 133 million annual live births in developing countries, about
798,000 (0.6%) are likely to present with permanent congenital and early-onset hearing loss
University of Ghana                              http://ugspace.ug.edu.gh
2(UNICEF, 2005). In most developing countries, routine screening programmes for hearing
impairment is either non-existent or their practice is minimal. This could be due to problems
involved in implementing screening programmes which underscores the need for consideration
of some protocols or factors towards effective implementation. In particular, some of these
protocols include the availability of qualified personnel to handle the exercise, societal
knowledge and acceptance of hearing impairment as a condition to slowing down a child’s
speech and language development, and the availability of modern equipment. Early childhood
screening will therefore help in identification of hearing problems in such children for early
rehabilitation.
1.2 PROBLEM STATEMENT
Hearing impairment is largely considered an ‘invisible’ disability, and studies have shown that
without any hearing screening a significant number of pre-school aged children may have
substantial hearing loss which could be unilateral or bilateral in nature, conductive or
sensorineural or both. A World Health Organization (WHO) report stipulated that hearing
impairment in children across the world constituted a particularly serious obstacle to their
optimal development and education, including language acquisition (WHO, 2010). This problem
is particularly disturbing since children are expected to develop competent language ability by
age 2. Hearing impairment in such pre-school children presents significant challenges to child
language or speech development.
In Ghana children are enrolled into pre-school at an early age without any official screening
protocol to identify suspected disabilities. As a result, children could struggle with one or
multiple disabilities, rendering academic work and general development very difficult. In view of
University of Ghana                              http://ugspace.ug.edu.gh
3this, the current educational reforms in Ghana stipulates that children should be screened for
hearing impairment at every entry point (starting level at each educational level) into formal
education to identify children with hearing disability. On the contrary and rather unfortunately,
this reform, though very laudable is not being done to achieve this goal. Another major problem
is the limited data on early childhood and pre-school hearing screening in Ghana. This presents
further challenges to implementing mediatory measures. In the light of all these setbacks, there is
the need for a study on pre-school hearing screening to estimate what the hearing status of the
pupils are and to also establish the prevalence of suspected hearing difficulties.
1.3 AIM
This study was aimed at screening pre-school pupils for suspected hearing loss and related
pathologies, and also determines the prevalence of hearing loss at various test frequencies for
purposes of early management and intervention.
1.4 SPECIFIC OBJECTIVES
The objectives of this study included:
 screening pre-school children for outer ear problems like wax impactation and suspected
hearing loss using pure tone screening audiometry and otoscopic examination
 determining the prevalence of hearing loss among the pre-school pupil
 investigating the existence of any significant associations between age, gender, and the
outcomes of the hearing screenings at test frequencies and otoscopic examinations
respectively.
 determining the pass and referral rates for right and left ears
University of Ghana                              http://ugspace.ug.edu.gh
41.5 RESEARCH QUESTION
The study was guided by the following research questions:
1. What is the prevalence of hearing loss among the pre-school pupil at each test frequency?
2. Is there any significant association between age, gender, and the outcomes of the hearing
screenings at test frequencies and otoscopic examinations respectively?
3. What are the pass and referral rates for right and left ears?
1.6 SIGNIFICANCE OF THE STUDY
This study was very relevant because it provided sufficient data on the hearing abilities of pre-
school children. It also underscored the need for future screening of pre-school children for
hearing difficulties or impairment at entry points into the school system.
University of Ghana                              http://ugspace.ug.edu.gh
5CHAPTER TWO
LITERATURE REVIEW
2.1 INTRODUCTION
This Chapter reviews relevant literature on the topic under study, for easy reference and better
understanding.
2.2 PREVALENCE OF HEARING IMPAIRMENT IN GHANA
Both children and adults in Ghana are often at high risk of undetected hearing impairment
(Amedofu and Fuente, 2008). Current attempts to limit the problem of hearing impairment
conditions through primary prevention are inadequate and sometimes ineffective  although  about
50% of the hearing impairment is believed to be preventable or avoidable (Smith, 2003). A
current activity aimed at preventing hearing impairment in Ghana involves the promotion of
immunization against known causes of hearing impairment such as measles, mumps and rubella;
improved care of maternal health before and during child delivery (Amedofu and Fuente, 2008).
The health delivery system in Ghana involves educating expectant and nursing mothers on the
dangers of hearing impairment and its consequences. Its aim of early identification, detection and
application of appropriate intervention has however not been achieved. For this reason, it became
necessary to identify cases of hearing impairment promptly through “secondary” prevention in
order to minimize its consequences or execute prompt treatment. Screening is the best-known
secondary prevention process for hearing impairment (Smith 2003).
University of Ghana                              http://ugspace.ug.edu.gh
62.3 PREVALENCE OF HEARING LOSS AMONG PRE-SCHOOL CHILDREN
Hearing loss is considered to be the most prevalent congenital abnormality in newborns and is
more than twice as prevalent as other conditions that are screened for at birth, such as sickle cell
disease, hypothyroidism, phenylketonuria, and galactosaemia (Finitzo and Crumley, 1995). It is
one of the most common sensory disorders and is the consequence of sensorineural and/or
conductive malfunctions of the ear. The impairment may also occur during or shortly after birth
and causes may be associated with genetic factors, trauma and disease. Hearing loss may be pre-
lingual (i.e., occurring prior to speech and language acquisition) or post-lingual (i.e., occurring
after the acquisition of speech and language). Since hearing loss in infants is silent and hidden,
great emphasis is placed on the importance of early detection, reliable diagnosis, and timely
intervention (Spivak et al., 2000). Even children presenting with mild or unilateral permanent
hearing loss may experience difficulties with understanding speech, especially in noisy
environments, and have problems with educational and psycho-social development (Bess et al.,
1988; Culbertson and Gilbert 1996).
Children with hearing loss frequently experience speech-language deficits and exhibit lower
academic achievement and poorer social-emotional development compared to their peers with
normal hearing (Yoshinaga‐Itano et al, 1998). The period from birth to 2 years is often
considered as the "critical period" for the development of normal speech and language. Normal
hearing in the first 6 months of life is also considered critical for normal speech and language
skills. Hence, early identification and appropriate intervention within the first 6 months of life
have been demonstrated to prevent or reduce many of the adverse consequences and to facilitate
language acquisition (Yoshinaga-Itano et al, 1998). Consequently, in countries with a high
University of Ghana                              http://ugspace.ug.edu.gh
7standard of health care, primary services include the early detection of congenital hearing loss
and the initiation of auditory habilitation before 6 months of age.
The prevalence of hearing loss in children in most developed countries is estimated to range
between 2-4children with moderate-severe hearing loss in every 1000 births. In contrast, only
limited information is available in developing countries, including the Middle East (especially in
the Arab countries), where the prevalence is estimated to be markedly higher than in Israel or
Europe and North America (Attias et al., 2006). In developing countries, more than 10 infants in
every 1000 births are estimated to be affected by a severe-profound hearing loss (Smith, 2003).
Post-newborn hearing screening is necessary in order to assist in the identification of hearing loss
that is late-onset or acquired, or not identified in early infancy. The American Academy of
Audiology (1997) recommends that all children should receive screening for hearing loss at least
once during their pre-school years. Additionally, the American Speech and Hearing Association
(ASHA) recommends screening for outer and middle ear disorders for all children age 7 months
through 6 years (ASHA, 1997). Several studies support the value of using aural acoustic
immitance measures for the identification of middle ear effusion in children (De Chicchis et al,
2000). Formal audiologic screening programmes are therefore particularly important in assisting
with the early identification and management of hearing and middle ear disorders during the
formative pre-school and school-age years (Mundy, 2001).
Pre-school programmes that provide audiologic screening services are becoming increasingly
available but lack universally accepted methods on administration. Such programmes may not
follow protocols recommended by professional standards and may use inadequately trained
University of Ghana                              http://ugspace.ug.edu.gh
8personnel to perform the screenings (Johnson, 2002). Therefore, the applied screening
procedures and referral and follow-up criteria differ among programs and may not be specific to
the professional guidelines for audiologic screening (ASHA, 1997). As such, varying screening
outcomes have been reported in the literature (Allen et al., 2004).
A prevalence survey in pre-school children by Hatcher et al., (1992) in Kenya reported 6.0%
failure with 8.7% prevalence of impacted wax in either. Another study conducted by Amedofu
and Brobby (1999) to determine prevalence of hearing impairment among some pre-school
children in Kumasi District of Ghana used a total of 960 pre-school children (566 males and 394
females) with an average age of 4.5 years. In this study, otoscopy and audiometric screenings
were performed. Audiometric screening was carried out at 1000 Hz, 2000 Hz and 4000 Hz and
for each ear a pass was defined as responding correctly to stimuli at 30 dBHL. The findings
indicated that 91.2% (n=881) passed and 8.2% (n=79) failed. Otoscopic examinations also
showed that 9.4% (n=89) were found with either unilateral or bilateral impacted wax.
2.4 IMPLICATIONS OF HEARING LOSS IN CHILDREN
Hearing loss can have an impact on language acquisition, speech, psycho-social well-being and
learning. The critical time to learn and stimulate the auditory and brain pathways is during the
first 6 months to 2 years. Children presenting with all degrees of hearing loss, and who receive
appropriate intervention prior to 6 months of age, can obtain speech and language skills
comparable to their hearing peers by age 3 years (Yoshinaga-Itano & Apuzzo, 1998). According
to the American Academy of Pediatrics (2003), ongoing review of hearing and speech age-
appropriate milestones, risk factors and routine hearing screening is critical. Unidentified hearing
impairments in the pre-school population are associated with speech and language delays,
University of Ghana                              http://ugspace.ug.edu.gh
9decreased attention span, and academic deficits (Roberts et al, 2002). Mild hearing loss can
significantly interfere with the reception of spoken language and education performance.
2.4.1 Audiologic Implications
Studies indicate that children with unilateral hearing loss (in one ear) are ten times as likely to be
held back at least one grade compared to children with normal hearing (Bess et al, 1998).
Chronic otitis media affects 5-30% of children aged 6 months to 11 years, and can persist for 4 to
5 months with or without medical intervention (Daly et al, 1999). During this period, a child is at
risk for a fluctuating hearing loss that can affect speech and language acquisition and auditory
processing (Roberts et al, 2002). In school, children must be able to listen in a noisy
environment, pay attention, concentrate, and interpret information. The linguistic skill of
interpreting information affects the reading success of the child. Therefore, a child with a hearing
loss is at a greater risk for academic deficits since hearing has an impact on the ability to learn
and how to read.
2.4.2 Communication Effects
Children with hearing loss typically exhibit delays and difficulty with tasks involving language
concepts, auditory attention and memory, and comprehension. They also have problems with
receptive and expressive language as well as syntax, semantics, and vocabulary development.
Speech perception and production is also a major problem (ASHA, 2011).
2.4.3 Academic Effects
Children with hearing loss may have problems in academic achievement, including language arts
and vocabulary. They may also demonstrate delays in development, reading, spelling, math, and
University of Ghana                              http://ugspace.ug.edu.gh
10
problem solving; these can lower scores on achievement and verbal IQ tests and therefore greater
need for enrollment in special education or support classes as well as increased need for
organization support in the classroom (ASHA, 2011)
2.4.4 Social Effects
Children may have self-described feelings of isolation, exclusion, embarrassment, annoyance,
confusion, and helplessness. They may refuse to participate in group activities and may act
withdrawn or sullen. Such children also exhibit lower performance on measures of social
maturity and have significant problems following directions (ASHA, 2011).
2.5 SIGNIFICANCE OF EARLY DETECTION
Prior to the advent of objective hearing screening test in developed countries, the median age of
identification varied from 10.4 months to 43.2 months depending on the degree of hearing loss
(Harrison et al., 2003). Parents were usually the first to suspect hearing impairment but
confirmation was always considerably delayed, sometimes by the physicians. This is due to lack
of knowledge and doubts about the possibility and efficacy of hearing screening in newborns and
infants (Kittrel and Arjmand, 1997).
In developing countries, parental suspicion prompted by a child’s inappropriate response, or lack
of response to environmental sounds is still the predominant mode of detection and occurs
usually at a mean age of 22 months (Gopal et al., 2001). Two objective screening tests currently
available for detecting infants with hearing loss are otoacoustic emission (OAE) and auditory
brainstem response (ABR).
University of Ghana                              http://ugspace.ug.edu.gh
11
Screening with OAE is an electro- physiologic measure of the integrity of the outer hair cells in
the cochlea. OAE, also known as cochlear echoes, are low intensity sounds originating from the
outer hair cells and can be elicited in response to clicks presented to the ear through a light
weight probe that houses both a transducer and microphone or receiver. The emission are
recorded and displayed in a wave form for interpretation in diagnostic instruments or simply
produce a “pass” or “refer” result in OAE screeners. The test is relatively quick, non-invasive
and does not require sleep, can be done readily for babies and acceptable to parents. The
recording often takes about one minute and can be administered without audiological expertise.
The ABR measures the electro physiologic function of the eighth cranial nerve and its pathways
in the brainstem. Response is significantly correlated with the degree of hearing impairment. In
general, the click-evoked threshold predicts behavioral audiometric threshold in the 1,000 to
4000 Hz range within 10 to 15 dB HL (Watkins, 2001).
2.6 ELEMENTS OF AUDIOMETRY
2.6.1 Test Environment
Threshold measurement may be affected in any test environment if the ambient noise levels
present at the time of the test is high. The evaluation should be conducted in a sound treated
environments designed specifically for hearing thresholds measurements. In cases where such
facilities are not available, every care should be taken to perform the evaluation in the quietest
room available.
The intensity level of sound in the testing room should not exceed 40 dispel (ANSI S3.1-1991)
as checked using a sound level meter. A room can receive sound treatment by using materials in
the room, which absorb sound. Covering the floor with any available carpeting or matting is
University of Ghana                              http://ugspace.ug.edu.gh
12
helpful. Acoustic tiles on the walls or ceiling can be used if available, otherwise more readily
accessible materials such as drapes on the walls can be used.
2.6.2 Controlling the Test Environment
There are many ways to control the test environment. The optimal test environment is quiet and
free of distractions. There should be no activity outside the test room that the listener can see or
hear. A person with normal hearing may be able to follow a conversation outside the test room
even if the ambient noise levels meet the level specified by ANSI S3.1-1991. While audible
speech would not mask the test tones, it would distract the listener, making a difficult test more
difficult yet. There is no such thing as a “soundproof” test room; i.e., a room which no outside
sound can penetrate. It is important that rooms are designed to attenuate nominal outside noise to
the point where it won’t mask the test signals, and it is just as important to not have unnecessary
noise generating activities in the area of the test room (ANSI, 1996).
2.6.3 Testing Protocol
Silverman et al., (1994) evaluated the sensitivity of pure tone survey of children with middle ear
effusion. The study comprised of 82 ears of children with confirmed middle ear effusion. The
results from the study indicated that the sensitivity to ASHA (1985) pure tone screening to
middle ear effusion were 54% (500 Hz excluded), 85% (500 Hz included), and 89% (250 Hz
included). The study recommended that 500 Hz as well as 1000 to 4000 Hz should be used in
pure tone screening at 20 dBHL for detection of middle ear effusion. The study also questioned
the assumption in the ASHA (1985) screening guidelines that passing a pure tone screening at
1000 Hz – 4000 Hz puts one at a low risk of hearing loss.
University of Ghana                              http://ugspace.ug.edu.gh
13
Walker et al., (2013) purported that in family practice, pure tone testing is typically done across
500 Hz – 4000 Hz to determine if a patient’s hearing falls within normal limits. The results assist
in patient referrals to an audiologist or ENT. This is done at 25 dB or 30 dB for adults, and 15 dB
to 20 dB for children.
2.7 PHYSICAL EXAMINATION OF THE EARS
A thorough physical examination is an essential part of evaluating a child for hearing loss.
Findings on head and neck examination associated with hearing impairment include difference in
coloration of the irises known as heterochromia, malformation of the auricle or ear canal,
dimpling or skin tags around the auricle, cleft lip or palate, asymmetry or hypoplasia of the facial
structures, and microcephaly (Grunfast et al, 1992). Abnormal increased distance between two
organs or bodily parts known as hypertelorism and abnormal pigmentation of the skin, hair, or
eyes also may be associated with hearing loss, as in Warrensburg syndrome.
Abnormalities of the eardrum should alert the physician to the possibility of hearing impairment.
A leading cause of acquired hearing impairment is otitis media with effusion (OME). Temporary
hearing loss has been demonstrated during episodes of acute otitis media. A child with repeated
or chronic otitis media is at high risk of acquired hearing impairment and should undergo hearing
evaluation (American Academy of Pediatrics, 1996). Pediatricians should be familiar with
pneumatic otoscopy and tympanometry as useful diagnostic tools in the management of OME.
University of Ghana                              http://ugspace.ug.edu.gh
14
CHAPTER THREE
METHODOLOGY
3.1    INTRODUCTION
This Chapter describes the methods and procedure adopted in carrying out the study. The details
consists of the research design, study site, sample population and size, samplings technique,
audiological test procedure, research instruments, data collection and data analysis. Data
management and ethical issues associated with the study are also included.
3.2     RESEARCH DESIGN
Cross sectional studies are particularly useful for studying prevalence of an illness and may also
support inferences of causes and effects. Carson et al., (2001) identifies cross sectional survey as
purely descriptive and used to assess the burden of a particular disease or disease prevalence in a
defined population. For these reasons, a cross sectional study design was adopted for this
research work.
3.3     STUDY SITE
Liliput Nursery and Kindergarten School (LiNKS) situated in the residential area of the Korle –
Bu Teaching Hospital (KBTH) was chosen as study site because of its relative proximity to the
Department of Audiology and Speech and Language Therapy of the School of Biomedical and
Allied Health Sciences. Another reason was its economic advantage in terms of transportation of
equipment and other logistics for the data collection.
University of Ghana                              http://ugspace.ug.edu.gh
15
3.4 STUDY POPULATION
The study population consisted of 150 nursery and kindergarten pre-school LiNKS pupils aged
3- 5 years. This age limit was chosen in accordance with the educational policy in Ghana which
defines pre-school pupils as children between ages 3 years to 5 years.
3.5 SAMPLE AND SAMPLING TECHNIQUES
According to Cohen et al., (2007), purposive sampling requires that samples in a study are
handpicked on the basis of their judgment of their typicality or possession of the particular
characteristics being sought. A population of 150 pupils between the ages 3 to 5 years was
purposively selected for the study.
3.6 INCLUSION AND EXCLUSION CRITERIA
3.6.1 Inclusion Criteria
All LiNKS pupils aged 3 – 5 years were included in the study.
3.6.2 Exclusion Criteria
The following criteria were used to exclude participants:
 All LiNKS children aged outside the 3-5 years bracket
 All non-LiNKS pre-school pupils
3.7 INSTRUMENTATION
The instrumentation included an HS-OT10C otoscope and two Audiometers namely, an
Interacoustics AD229e 2-channel audiometer and a Maico MA 40 audiometric screener
University of Ghana                              http://ugspace.ug.edu.gh
16
incorporating a built-in Rs 232 interface for data transfer to a computer. The audiometers were
calibrated and connected to TDH 39 headphones (Table 3.1 and Fig. 3.1).
Table 3.1: Technical specifications of audiometers
Type of audiometer
Interacoustics AD 229e Maico MA40
Components TDH 39 audiometer headset TDH 39 audiometer headset
UP 5400 External power supply:100-240V External power supply: 100-240V
Connection to TDH 39 headphones
TDH 39 headphones
Bowl of marbles
Fig. 3.1: Schematic flowchart of pure tone audiometry
The calibrated audiometers were used for behavioral measurements. Biologic calibration was
done using an individual with known hearing thresholds in order to establish the consistency of
the equipment on the day of testing.
3.8 AUDIOLOGICAL SCREENING TEST
Conditioned play audiometry presented by air conduction under headphones using warble tone
was used to screen the pupils. To pass the screening, the child must respond to at least two out of
three tone presentations at all frequencies in both ears. The screening was performed in the
Audiometer
University of Ghana                              http://ugspace.ug.edu.gh
17
headmistress office as it provided a relatively quiet environment conducive for the screening
exercise. Initially, demographic information on pupils was recorded followed by an otoscopic
examination. The outcomes of otoscopic examination were categorized as pass or refer: A pass
means ear canal with a visible tympanic membrane where as a referral constituted an ear canal
completely blocked with wax and/or any foreign material. Hearing screening was subsequently
conducted with 30 dBHL and 25 dBHL at 500 Hz and 1000 Hz, 2000 Hz, 4000 Hz, 6000 Hz
respectively using a warble test tone, initially conditioning with a 50dBHL warble tone. An
average 31 dB ambient noise level was measured during the screening process.
Although ASHA (1997) recommends pure tone hearing screening to be conducted at 1000 Hz,
2000 Hz and 4000 Hz, the current study incorporated hearing screening at 500 Hz and 6000 Hz
for the detection of middle ear effusion and also for experimental purposes as recommended by
Silverman et al., 91994) and Walker et al., 92013)..
3.9 PROTOCOL FOR TESTING AND DATA COLLECTION
The following test protocol was used for testing and data collation.
1. Perform otoscopic inspection of each ear canal. In the event of complete occlusion
(impacted cerumen), foreign object, visible signs of ear disease.
2. Seat the child in a chair next to the table with the audiometer and condition the child to
the test. This is done by asking the child to listen and pick small balls on a table into a
basket any time sounds are heard in either ear, in this case sounds are made audible
enough to be heard by child (e.g., 1000 Hz at 50 dBHL), and then the child is assisted
with the desired response till they are able to respond independently.
University of Ghana                              http://ugspace.ug.edu.gh
18
3. Set the attenuator to 30 dBHL at 500 Hz and 25 dBHL at 1000 Hz, 2000 Hz, 4000 Hz
and 6000 Hz and present the tone to obtain responses from tone presentations for pass or
refer.
4. Interpret and record screening results. To pass the screening, the child must respond to at
least two out of three tone presentations at all frequencies in both ears (ASHA, 1997).
5. Arrange for referral or follow-up as needed.
3.10 ETHICAL CONSIDERATIONS
Ethical clearance was obtained from the Ethics and Protocol Review Committee of the School of
Allied Health Sciences before the commencement of the data collection. Permission to
commence the data collection was sought from the Head of the School serving at the study site.
Participation of subjects conformed to the required ethical guidelines regarding the use of human
subjects. Written informed consent was sought from parents of each participant before data
collection with the objectives, methods of the study, and the testing process duly explained.
Additionally, participants were assured of strict confidentiality with regards to their bio-data and
any data generated by the study.
3.11 DATA ANALYSIS
Descriptive and inferential statistics was used to present, describe, and interpret the data in light
of the research questions set for the study. Cohen et al., (2007) explained that descriptive
statistics do exactly what they say; that is, they describe and present data.
University of Ghana                              http://ugspace.ug.edu.gh
19
CHAPTER FOUR
RESULTS
4.1     INTRODUCTION
The results of the study are presented in this Chapter. Described via descriptive and inferential
statistics in respect of demographics, otoscopic examinations, pure tone audiometric screening,
the results show the prevalence of hearing loss at defined test frequencies, the existence of any
significant associations between age, gender, and the outcomes of the hearing screenings at test
frequencies and otoscopic examinations respectively.
4.2 DESCRIPTIVE STATISTICS
4.2.1 Demographic Characteristics
The age and gender demographics of the pre-school children are presented in Table 4.1.
Table 4.1: Age and gender distributions
Age (years) Number Percent (%)
Age distribution
3 92 61.3
4 19 12.7
5 39 26.0
Total 150 100.0
Average age = 3.00 ± 0.27 years
Gender distribution
Males 79 52.7
Females 71 47.3
Total 150 100.0
University of Ghana                              http://ugspace.ug.edu.gh
20
The largest population was constituted by the 3 year olds (n=92, 61.3%) while the 4 year olds
constituted the least population of 19 (12.7%). The mean age of the children was 3.00 ± 0.27
years. The breakdown for gender indicated more males (n=79, 52.7%) than females (n=71,
47.3%).
4.2.2 Otoscopic Examination and Hearing Screening Results
Otoscopic examination was conducted in both ears of the 150 children to establish a pass/refer.
Subsequently, pure tone audiometric screening tests were conducted across six test frequencies:
500 Hz at 30dB, and 1000 Hz, 2000 Hz, 4000 Hz, 6000 Hz at 25dB. The results were
categorized as either “pass” or “refer” for both genders. The distribution of hearing screening
results at test frequencies for both ears is presented in Tables 4.2.
Table 4.2: Distribution of hearing screening results at test frequencies
Ear Results
Test Frequencies (Hz) Total
500 1000 2000 4000 6000
Right
Pass 131 141 144 141 136 693
Refer 19 9 6 9 14 57
Left
Pass 128 138 139 137 136 678
Refer 22 12 11 13 14 72
Combined
Pass 259 279 283 278 272 1371
Refer 41 21 17 22 28 259
Most of the “pass” results were recorded in the 1000 Hz- 4000Hz range in both ears, with the
least observed at 500 Hz. The opposite trend was registered for the “refer” test results. The
number of passes in the right ear (n=693, 46.2%) marginally exceeded that in the left ear (n=678,
45.2). Overall there were more “passes” (n=1371, 91.4%) compared to “refers” (n=129, 8.6%).
University of Ghana                              http://ugspace.ug.edu.gh
21
The prevalence of hearing loss estimated at the test frequencies for both ears is shown in Table
4.3.
Table 4.3: Prevalence of hearing loss at test frequencies for right and left ears
Test frequency (Hz) Prevalence of hearing loss (%)
500 14.0
1000 7.0
2000 6.0
4000 7.0
6000 9.0
From Table 4.3, the highest prevalence of hearing loss were registered at 500 Hz (14%) and 6000
Hz (9.0%), while a prevalence of 6.0% - 7.0% was recorded for test frequencies of 1000 Hz –
4000 Hz.
4.3 INFERENTIAL STATISTICS
Inferential statistics was applied to analyze the otoscopic examinations and pure tone audiometry
results for purposes of establishing any associations with age and gender.
4.3.1 Association between Otoscopy and Age
The detailed otoscopy results presented in Table 4.4 revealed no significant association between
the outcome of otoscopic examination for both right and left ears and the age of participants [χ2
((2, n= 150) = 3.80, p> 0.05]. Among the 3 year olds, 88 (95.7%) and 85 (92.4%) passed the
otoscopic examinations in the right and left ears, while 4 (4.3%) and 7 (7.6%) failed respectively.
University of Ghana                              http://ugspace.ug.edu.gh
22
Table 4.4: Association between otoscopy and age for right and left ears
Age (years) Pass Refer Total χ2 p-value
Right ear
3 88 4 92 1.20 0.67
4 17 2 19
5 37 2 39
Total 142 8 150
Left ear
3 85 7 92 0.19 1.00
4 17 2 19
5 36 3 39
Total 138 12 150
*Significant at 0.05
Equal “pass” and “refer” rates were observed for the 4 year olds in both ears (Pass: n=17, 89.5%,
Refer: n=2, 10.5%). For the 5 year olds, a similar trend was recorded involving 37 (94.9%) and
36 (92.3%) passes in the right and left ears, and 2 (5.1%) and 3 (7.7%) were referred
respectively.
4.3.2 Association between Pure Tone Audiometry and Age
Pure tone audiometric screening test was conducted on each participant at an intensity level of 30
dBHL across the spectrum of test frequencies. The results which were analyzed to investigate
any statistical significance between pure tone audiometric screening and age in both ears for each
test frequency are shown Tables 4.5 – 4.9.
University of Ghana                              http://ugspace.ug.edu.gh
23
Table 4.5: Association between pure tone audiometry and age for both ears at 500Hz
Age (years) Pass Refer Total χ2 p-value
Right ear
3 78 14 92
3.30 0.21
4 19 0 19
5 34 5 39
Total 131 19 150
Left ear
3 77 15 92
3.80 0.15
4 19 0 19
5 32 7 39
Total 128 22 150
*Significant at 0.05
The chi-square estimates of Table 4.5 {χ2 [(2, n= 150) = 3.30, p = 0.21> 0.05]}, and {χ2 [(2, n =
150) =3.80, p= 0.15> 0.05]} showed no significant association between the outcome of the pure
tone hearing screening and age of pre-school children for both ears at 500Hz. The number of
passes for the 3 year olds were highest (right ear: n=78, 84.8%; left ear: n=77, 83.7%) compared
to the 4 year olds (right ear: n=19, 100%; left ear: n=19, 100%) and 5 year olds (right ear: n=34,
87.2%; left ear: n=32, 82.0%) respectively. More children were referred among the 3 year olds
(right ear: n=14; 15.2%; left ear: n=15, 16.3%) than the 5 year olds (n=5, 12.8%; left ear: n=7,
18.0%). No “refer” cases were recorded for the 4 year olds.
University of Ghana                              http://ugspace.ug.edu.gh
24
Table 4.6: Association between pure tone audiometry and age for both ears at 1000Hz
Age (years) Pass Refer Total χ2 p-value
Right ear
3 87 5 92
2.52 0.31
4 19 0 19
5 35 4 39
Total 141 9 150
Left ear
3 86 6 92
1.70 0.55
4 18 1 19
5 34 5 39
Total 138 12 150
*Significant at 0.05
At 1000 Hz frequency, no significant association between pure tone hearing screening and age
was established among the pre-school children in both ears as suggested by the inferential
statistics (right ear: χ2 [(2, n= 150) = 2.52, p=0.31> 0.05]; left ear: χ2 [(2, n= 150) = 1.70,
p=0.55> 0.05]). Table 4.6 shows higher number of passes among the 3 year olds (n=87, 94.6%;
left ear: n=86, 93.5%). The number of “refers” were fewer (n=9) in the right ear compared to the
left ear (n=12). The referred cases among the 5 year olds were fractionally lower (n=9) than the 3
year olds (n=11) for both ears. A single (5.3%) “refer” case was recorded for the 4 year olds.
Table 4.7 depicts a non-significant association between the hearing screening outcome and the
children’s age at 2000 Hz for both right (χ2 =0.95, p-value= 0.73> 0.05) and left (χ2 =2.34, p-
value= 0.35> 0.05) ears.
University of Ghana                              http://ugspace.ug.edu.gh
25
Table 4.7: Association between pure tone audiometry and age for both ears at 2000Hz
Age Pass Refer Total χ2 p-value
Right ear
3 88 4 92
0.95 0.73
4 19 0 19
5 37 2 39
Total 144 6 150
Left ear
3 87 5 92
2.34 0.35
4 18 1 19
5 34 5 39
Total 139 11 150
*Significant at 0.05
The total pass rates for the different age groups for the right ear were higher (n=144, 96.0%)
than in the left ear (n=139, 92.7%). The “refer” rates were however higher in the left ear (n=11,
7.3%) than in the right ear (n=6, 4.0%).
The statistics of Table 4.8 showed non-significant associations between the hearing screening
outcome for both right ears (χ2 [(2, N= 150) = 1.69, p=0.43> 0.05]) and left ears (χ2 [(2, N= 150)
= 0.40, p=0.85> 0.05]) at 4000Hz respectively while the largest number of “passes” were
recorded for the 3 year olds (right ear: n=85, 92.4%; left ear: n=84, 91.3%). As observed, the
“refer” rates were higher for left ear (n=13, 8.7%) than right ears (n=9, 6.0%).
University of Ghana                              http://ugspace.ug.edu.gh
26
Table 4.8: Association between pure tone audiometry and age for both ears at 4000Hz
Age Pass Refer Total χ2 p-value
Right ear
3 85 7 92
1.69 0.434 19 0 19
5 37 2 39
Total 141 9 150
Left ear
3 84 8 92
0.40 0.85
4 18 1 19
5 35 4 39
Total 137 13 150
Table 4.9: Association between pure tone audiometry and age for both ears at 6000Hz
Age Pass Refer Total χ2 p-value
Right ear
3 81 11 92
2.82 0.254 19 0 19
5 36 3 39
Total 136 14 150
Left ear
3 83 9 92
2.54 0.30
4 19 0 19
5 34 5 39
Total 136 14 150
*Significant at 0.05
University of Ghana                              http://ugspace.ug.edu.gh
27
At 6000 Hz (Table 4.9), no significant association between the hearing screening outcome and
age was found for both ears as indicated by the statistics (right ear: χ2 [(2, N= 150) = 2.82,
p=0.25 > 0.05]; left ear: χ2 [(2, N= 150) = 2.54, p=0.30> 0.05].The total number of passes and
referrals recorded for all the age categories in both ears were equal (pass: n=136, 90.7%; refer:
n=14, 9.3%). No case of referrals was recorded for the 4 year old children.
The variations of test frequency with pass and referral rates for the different age groups of the
pre-school children are shown in Figs. 4.1 and 4.2 respectively.
Fig. 4.1: Frequency variation with pass rate for different age groups
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
160.0
0 1000 2000 3000 4000 5000 6000 7000
N
u
m
be
r 
o
f p
a
ss
es
Test frequency (Hz)
Pass rate (right ear)  3 years
Pass rate (right ear) 4 years
Pass rate (right ear) 5 year
Pass rate (right ear) Total
Pass rate (left ear) 3 years
Pass rate (left ear) 4 years
Pass rate (left ear) 5 years
Pass rate (left ear) Total
University of Ghana                              http://ugspace.ug.edu.gh
28
Fig. 4.2: Frequency variation with referral rate for different age groups
4.3.3 Association between Pure Tone Audiometry and Gender
The association between pure tone audiometric hearing screening and gender in both ears for
each test frequency was also investigated. The results are shown Tables 4.10 – 4.15.
Table 4.10: Association between pure tone audiometry and gender for both ears at 500Hz
Frequency
=500Hz
Male Female Combined χ2 p-
valuePass Refer Total Pass Refer Total Pass Refer Total
Right ear
Number 69 10 79 62 9 71 131 19 150 0.00 1.00
Percent 87.3 12.7 100.0 87.3 12.7 100.0 87.3 12.7 100.0
Left ear
Number 69 10 79 59 12 71 128 22 150 0.54 0.460
Percent 87.3 12.7 100.0 83.0 17.0 100.0 85.3 14.7 100.0
*Significant at 0.05
0
5
10
15
20
25
0 1000 2000 3000 4000 5000 6000 7000
N
u
m
be
r 
o
f r
ef
er
ra
ls
Test frequency (Hz)
Referral rates (right ear)  3 years
Referral rates (right ear) 4 years
Referral rates (right ear) 5 year
Referral rates (right ear) Total
Referral rates (left ear) 3 years
Referral rates (left ear) 4 years
Referral rates (left ear) 5 years
Referral rates (left ear) Total
University of Ghana                              http://ugspace.ug.edu.gh
29
The statistics showed no significant association between pure tone audiometric hearing screening
and gender for both right (χ2 [(1, N= 150) = 0.00, p=1.00 > 0.05]) and left ears (χ2 [(1, N= 150) =
0.54, p =0.46 > 0.05]) at 500Hz was established. Sixty nine (87.3%) males passed in both ears
while 62 (87.3%) and 59 (83.1%) females passed in the right and left ears respectively. There
were less referrals for both gender in both ears (male: n=20, 25.3%; females: n=21, 29.6%).
Table 4.11: Association between pure tone audiometry and gender for both ears at 1000Hz
Frequency
=1000Hz
Male Female Combined χ2 p-
valuePass Refer Total Pass Refer Total Pass Refer Total
Right ear
Number 72 7 79 69 2 71 141 9 150 2.42 0.12
Percent 91.1 9.9 100.0 97.2 2.8 100.0 94.0 6.0 100.0
Left ear
Number 73 6 79 65 6 71 138 12 150 0.04 0.85
Percent 92.4 7.6 100.0 91.5 8.5 100.0 92.0 8.0 100.0
*Significant at 0.05
At 1000 Hz, 72 (91.1%2.8%) males and 69 (97.2%) females passed while 7 (8.9%) males and 2
(2.8%) females referred respectively in the right ear. Similarly, 73 males (92.4%) and 65 (91.6%)
females passed in the left ear, while 6 each of both gender were referred. The statistics showed
no significant association between the hearing screening outcome for both ears (right ear: χ2 [(1,
N= 150) = 2.42, p= 0.12 > 0.05]; left ear: χ2 [(1, N= 150) = 0.04, p=0.85> 0.05]).
Table 4.12 also revealed a non-significant association between the hearing screening outcome
and gender for both right ears (right ear: χ2 = 0.49, p=0.48> 0.05; left ear: χ2 = 0.25, p=0.62 >
0.05).
University of Ghana                              http://ugspace.ug.edu.gh
30
Table 4.12: Association between pure tone audiometry and gender for both ears at 2000Hz
Frequency
=2000Hz
Male Female Combined χ2 p-
valuePass Refer Total Pass Refer Total Pass Refer Total
Right ear
Number 75 4 79 69 2 71 144 6 150 0.49 0.48
Percent 94.9 5.1 100.0 97.2 2.8 100.0 96.0 4.0 100.0
Left ear
Number 74 5 79 65 6 71 139 11 150 0.25 0.62
Percent 94.7 6.3 100.0 91.5 8.5 100.0 92.7 7.3 100.0
Out of 79 males, 75 (94.9%) and 74 (93.7%) passed respectively in right and left ears, while 4
(5.1%) and 5 (6.3%) failed in the right and left ears. The pass and refer rates among the 71
females were 69 (97.2%) and 2(2.8%) for right ears and 65(91.4%) and 6 (8.5%) for left ears.
Table 4.13: Association between pure tone audiometry and gender for both ears at 4000Hz
Frequency
= 4000Hz
Male Female Combined χ2 p-
valuePass Refer Total Pass Refer Total Pass Refer Total
Right ear
Number 74 5 79 67 4 71 141 9 150 0.03 0.86
Percent 94.7 6.3 100.0 94.4 5.6 100.0 94.0 6.0 100.0
Left ear
Number 74 5 79 63 8 71 137 13 150 1.15 0.28
Percent 94.7 6.3 100.0 88.7 11.3 100.0 91.3 8.7 100.0
*Significant at 0.05
The results of Table 4.13 showed no significant association between the hearing screening
outcome and gender for both right ears (right ear: χ2 = 0.03, p=0.86> 0.05; left ear: χ2 = 1.15,
p=0.28 > 0.05). Seventy four 74 (93.7%) and 5 (6.3%) males passed and failed in both right and
University of Ghana                              http://ugspace.ug.edu.gh
31
left ears respectively. The pass and refer rates among the females were 67(94.4%) and 4 (5.6%)
for right ears and 63 (88.7%) and 8 (11.3%) for left ears.
At 6000 Hz, the statistical estimates (Table 4.14) also showed no significant association between
the hearing screening outcome and gender for both right ears (right ear: χ2 = 0.12, p= 0.73> 0.05;
left ear: χ2 = 0.04, p=0.28 > 0.05).
Table 4.14: Association between pure tone audiometry and gender for both ears at 6000Hz
Frequency
=6000Hz
Male Female Combined χ2 p-
valuePass Refer Total Pass Refer Total Pass Refer Total
Right ear
Number 71 8 79 65 6 71 136 14 150 0.12 0.73
Percent 89.9 10.1 100.0 94.4 5.6 100.0 90.7 9.3 100.0
Left ear
Number 72 7 79 64 7 71 136 14 150 0.04 0.28
Percent 91.1 8.9 100.0 90.1 9.9 100.0 90.7 9.3 100.0
*Significant at 0.05
Among the 79 males, 71 (89.9%) and 72 (91.1%) passed in the right and left ears, while 8
(10.1%) and 7 (8.9%) failed in the respective ears. For the female children, 65(94.4%) and 64
(90.1%) passed in the right and left ears, while 6 (5.6% and 7 (9.9%) failed respectively. The
number of total passes (n=136, 90.7%) and refers (n=14, 9.3%) were the same for both ears
University of Ghana                              http://ugspace.ug.edu.gh
32
CHAPTER FIVE
DISCUSSION
5.1       INTRODUCTION
The results of the pre-school hearing screening study conducted at LiNKS School in the Korle
Bu Metropolis are discussed in this Chapter. The discussions are guided by the research
questions set for the study.
5.2 DEMOGRAPHICS
A population of 150 pre-school children aged between 3 and 5 years distributed in three classes
were screened via otoscopy and pure tone audiometry for hearing loss. The calculated average
age of 3.00± 0.27 years was closer to the 3 year olds because this group constituted the largest
population (n=92, 61.3%) of the pre-schoolers. The gender distribution indicated a relatively
larger population of males (n=79, 52.7%) than females (n=71, 47.3%).
5.3 AUDITORY SCREENING
5.3.1 Outcome of Otoscopic Examination
From the outcome of the otoscopic examinations conducted in both ears of the 150 children,
there was a general observation of more “passes” compared to “refers” and this is suggestive that
most of the children had normal ear canal.
From the inferential statistics, the study revealed no significant association between the outcome
of otoscopic examination for both right and left ears and the pre-school children’s age as
indicated via the estimated p-values of 0.67 (right ear) and 1.00 (left ear) respectively. A
University of Ghana                              http://ugspace.ug.edu.gh
33
common trend of more passes (right ear: n=142, 94.7%, left ear: n=138, 92.0%) than referrals
(right ear: n=8, 5.3%; left ear: n=12, 0.8.0%) was observed for all the age groups
5.3.2 Pure tone Screening Audiometry
The highest prevalence of hearing loss were registered at 500 Hz (14.0%) and 6000 Hz (9.0%)
where the least numbers of “passes” and most numbers of “refers” were recorded. The lowest
prevalence rates of 6.0% - 7.0% were estimated in the1000 Hz – 4000 Hz range. This
observation agrees with earlier findings of the work by Al-Kandari and Alshuaib (2010) that
majority of children were referred at lowest frequency of 500Hz and attributed the cause to
possible wax impactation in the ear canal of most children. The high prevalence of hearing loss
registered in the current study may also be due to the occurrence of middle ear effusion and or
wax impactation.
Inferential statistics were applied to analyze the pure tone audiometry screening results across
the spectrum of test frequencies. This was done to establish any associations with age and
gender. The chi-square and p-values estimated at different test frequencies (500 Hz – 6000 Hz)
showed a common and consistent trend of no significant association between the outcome of the
pure tone hearing screening and age of pre-school children for both ears. According to the
literature, hearing loss tends to increase with age (Amedofu, 2006). Hence it was anticipated that
the 5 year olds would have presented with higher prevalence of “refers”. However, due to the
relatively larger population of the 3 year old group, the number of “passes” and “refers” were
highest among this group of children compared to the 4 year old and 5 year old children
respectively.
University of Ghana                              http://ugspace.ug.edu.gh
34
In general, the total pass rates were higher in the right ear than in the left ear for each age group
and for each test frequency. The highest pass rates were recorded at 2000 Hz. The inter-
frequency variations in the pass rates for the three categories of ages were minimal. The relative
changes were almost constant across the test frequency spectrum for the 4 year and 5 year olds.
Conversely, the number of “refers” was higher in the left ear than in the right ear. No consistent
trend was observed in the inter-frequency variation of referral rates with age. As noted for the
pass rate, the least referrals were recorded at 2000 Hz for both the 3 year olds, 5 year olds and
combined age for right ear.
The data gathered from the 150 pupils screened via pure tone audiometry also showed that
91.4% passed in either one ear or both for the initial screening. This is consistent with the pass
rate of 91.8% observed by Amedofu and Brobby (1999). The 8.6 % referral rate in either one or
both ears obtained in this study is also consistent with the observations of Amedofu and Brobby
(1999) but higher than the rate reported by Bal and Hatcher (1992). This failure could be
attributed to a variety of reasons ranging from environmental influence such as background noise
and some disturbances from their colleagues, poor conditioning, inattention on the part of the
testee, foreign body in the ear, impacted cerumen, a middle ear pathology, problems with the
sensory and neural portion of the auditory system, and errors arising from the tester. This is
supported by the findings of McCarter et al, (2007) who observed that cerumen is a naturally
occurring, normally extruded product of the external auditory canal. It is usually asymptomatic,
but can cause complications such as hearing loss pain, or dizziness when it becomes impacted, as
well as interfering with examination of the tympanic membrane. As noted by McCarter et al.,
(2007) that wax and/or any other condition in the ear could cause hearing loss, the implications
of this failure rate are therefore very critical.
University of Ghana                              http://ugspace.ug.edu.gh
35
Roland et al., (2008) posted that cerumen impactation is a common problem encountered by the
general physician, the family physician and the otolaryngologist almost every day. They noted
that some 2–6% of the general population in the United Kingdom suffers from cerumen
impactation at any given time, suggesting a prevalence of 6–18 million individuals.
With respect to gender, the same statistical observations were made. In particular, the χ2 tests of
association at different test frequencies (500 Hz – 6000 Hz) showed a common and consistent
trend of no significant association between the outcome of the pure tone hearing screening and
gender of pre-school children for both ears. The findings of the study are consistent with the
published work of Lu et al (2011) which also established no significant correlation between
hearing loss and gender among pre-school children. On the contrary, a study conducted in Iran
showed hearing loss was significantly more common in boys (Sarafraz & Ahmadi, 2009).
In general, the outcome of association between age and gender, and hearing loss in the current
study may be due to the fact that there is no significant difference in the physical and
physiological activities of 3, 4 and 5 years old children, and also regardless of gender. The fact
that more number of males and females “passed” the screening tests in both ears, and fewer
numbers of children had “refers” regardless of age and gender is suggestive that prevalence of
hearing loss is less at younger ages for both males and females as further confirmed by Rose et
al., (2003).
University of Ghana                              http://ugspace.ug.edu.gh
36
CHAPTER SIX
CONCLUSIONS AND RECOMMENDATIONS
6.1 INTRODUCTION
A study on pre-school hearing screening in a selected nursery school in Korle Bu, Accra, Ghana
has been done. This Chapter presents the summary of the research findings, conclusion and some
recommendations.
6.2 SUMMARY OF THE STUDY
The study was aimed at screening pre-school pupils for suspected hearing loss and related
pathologies and to determine the prevalence of hearing loss at test frequencies for purposes of
early management and intervention. Additionally to these, the study:
 Ascertained the existence of any significant associations between age, gender, and the
outcomes of the hearing screenings at test frequencies and otoscopic examinations
respectively, and
 Determined the pass and referral rates for right and left ears for both gender and at
different ages.
Out of the 150 pre-school children screened via otoscopy and pure tone audiometry, 91.4 %
passed in either one ear or both for the hearing screening and 8.6% referred in either one or both
ears. The referral rate or percentages could be attributed to several factors ranging from the
presence of middle ear pathology, wax impaction, failure to comprehend test instruction and
University of Ghana                              http://ugspace.ug.edu.gh
37
environmental factors. More so, the test of association at different test frequencies (500 Hz –
6000 Hz) showed a common and consistent trend of no significant association between the
outcome of the pure tone hearing screening and age/gender of pre-school children for both ears
6.3 CONCLUSION
The results from the study affirmed that hearing screening was very necessary at the pre-school
level and provides a baseline for building a more comprehensive pre-school hearing screening
protocol for early identification and detection of hearing loss.
6.4 RECOMMENDATION
Based on the findings of the study, the following recommendations were made:
 Hearing screening in pre-school children should be encouraged in all nursery and
kindergarten schools across the country.
 Awareness should be made to parents and guardians about the importance of early
childhood screening
 Children identified with hearing problems should be refereed to audiology centers for
further assessment and for rehabilitation
 Hearing screening protocols for preschool children in Ghana should include 500 Hz.
6.5 LIMITATION OF STUDY
Pre-school hearing screening is very important for detection of early childhood hearing loss and
therefore the study should have provided room to cover a number of schools. However, the lack
of competent audiological staff and equipment limited the study to only one selected school.
University of Ghana                              http://ugspace.ug.edu.gh
38
Generally, audiometric hearing assessment including hearing screening is carried out in a sound
proof booth. However the hearing screening at LiNKS was done in the head teacher’s office
which could be termed an unsuitable environment for testing hearing. The nursery school where
the study was done has accommodation problems in terms of class rooms and that compelled
authorities to combine nursery and kindergarten thereby making it impossible to separate and
compare results of nursery and kindergarten children.
University of Ghana                              http://ugspace.ug.edu.gh
39
REFERENCES
Al-Kandari, J. M., & Alshuaib, W.B. (2010). Hearing evaluation of school children in Kuwait.
Electromyoclin Nerophysiology.50 (6); 309-318.
Allen, R. L., Stuart A., Everett, D, & Elangovan, S (2004). Preschool hearing screening:
Pass/refer rates for children enrolled in a Head Start program in eastern North Carolina.
American Journal of Audiology.13; 29–38.
Amedofu, G.K., Ocansey, G., & Barbara, B.A. (2006). Characteristics of hearing-impairment
among patients in Ghana. African Journal of Health Sciences. 13; 110-116.
Amedofu, G.K., &Brobby, G.W (1999).Patterns of pre-school hearing impairment among
kindergarten school children in Kumasi District, Ghana. Ghana Journal of Science.
36,127-131.
Amedofu, G.K., & Fuente, A. (2008). Occupational hearing loss in developing countries.
Audiology for developing countries. 121-125
Amedofu, G.K., Brobby, G.W., & Ocansey, G. (1997).The causes and prevalence of preschool
deafness in Ghana. African Journal of Health Sciences.4:29-32.
Amedofu, G.K., & Fuente. A. (2008). In Occupational Hearing Loss in Developing Countries
New York: Nova Science Publishers Inc.
American Academy of Audiology (1997). Identification of middle ear dysfunction in pre-school
and school age children. Available at
http//www.audiology.org/resources/documentlibrary/pages/hearinglosschildren.aspx.199
University of Ghana                              http://ugspace.ug.edu.gh
40
American Academy of Audiology (2011). Childhood Hearing Screening Guidelines. Available at
http://www.infanthearing.org/resourceshome/positionstatements/docs ps/AAA Guidelines
2011.pdf.
American Academy of Pediatrics (1996). Recommendations for preventative pediatric health
care. Pediatrics.105, 645–646.
American Academy of Pediatrics (2003). Prevention of Pediatric Overweight and obesity.
Pediatrics, 112 (2), 424-430
American-Speech-Language-Hearing Association (1972). Guidelines for Identification
Audiometry.21, 98-102.
American-Speech-Language-Hearing Association (1985). Guidelines for Identification
Audiometry. ASHA 27, 49- 52.
American-Speech-Language-Hearing Association (1997). Guidelines for Hearing Screening.17,
94-99.
American-Speech-Language-Hearing Association (2011). Guidelines for Hearing Screening.17,
94-99.
American-Speech-Language-Hearing Association (2012). Guidelines for audiometric symbols.
Rockville, MD: Author.
Anderson, K.L. (2011). Hearing screening in early childhood: What, Why, How.
http://successforkidswithhearingloss.com/wp-content/uploads/2011/12/Handout-Hearing-
Screening-in-Early-Childhood.pdf.2011.
Anna, F.B.S., Heidi, R., & Margaret, K.M.D (2004). Causes of hearing loss for parents and
families. Harvard Medical School Center for Hereditary Deafness.
University of Ghana                              http://ugspace.ug.edu.gh
41
American National Standards Institute (1991). Draft Standard for the Evaluation of Hearing
Conservation Program. ANSI S12.13.
American National Standards Institute (ANSI) (1996). Specifications for audiometers. ANSI
S3.6.
Attias, J., Al-Masri, M., Abukader, I., Cohen, G., Merlov, P., & Pratt, H, et al. (2006). The
prevalence of congenital and early-onset hearing loss in Jordanian and Israeli infants.
International Journal of Audiology.45, 528-536.
Bess, F.H., Dodd-Murphy, J., & Parker, R.A (1988). Children with minimal sensorineural
hearing loss: Prevalence, educational performance, and functional status. Ear and
Hearing. 19(5), 39-54.
Bolajoko, O.O. (2008). The need for standardization of methods for worldwide infant hearing
screening. The Laryngoscope, 188(10), 1830-1836.
British Association of Otolaryngology and British Society of Audiology (1983).Method for
assessment of hearing disability. British Journal of Audiology.17, 203-212.
Carney, A.E., & Moeller, M.P (1997). Treatment Efficacy: Hearing Loss in Children. Journal of
Speech, Language, and Hearing Research 41, 61-84.
Clark, J.G. (1981).Uses and abuses of hearing loss classification. ASHA 23:493-500
Carson, D., Gilmore, A., Gronhaug, K. & Perry (2001). Qualitative Research in Marketing Sage,
London.
Cohen, J.Y., Pouget, P., Woodman, G.F., Subraveti, C.R., Schall, J.D., & Rossi, A.F. (2007).
Difficulty of visual search modulates neuronal interactions and response variability in the
frontal eye field. J. Neurophysiol. 98, 2580–2587
University of Ghana                              http://ugspace.ug.edu.gh
42
Daly K., Hunter L., & Giebink, G (1999). Chronic otitis media with effusion. Pediatrics in
Review, 20(3), 85‐93.
De Chicchis, A.R., Todd, N.W., & Nozza, R.J (2000). Developmental changes in aural acoustic
admittance measurements. American Journal of Audiology, 11, 97–102.
Finitzo, T., & Crumley, W.G (1995). The role of the pediatrician in hearing loss from detection
to connection. Pediatric Clinics of North America.
Gopal, R., Hugo, S.R., & Louw, B. (2001). Identification and follow up of children with hearing
loss in Mauritius. International Journal Pediatric Otorhinolaryngology, 57, 99-113.
Grunfast, K.M., & Lalwani, A.K. (1992). Practical approach to diagnosis and management of
hereditary hearing impairment (HHI).Ear Nose Throat J.71 (10):479–493.
Harrison, M., & Roush, J.W. (2003).Trends in Age of Identification and Intervention in Infants
with Hearing Loss. Ear and Hearing. 24, 89-95.
Hatcher, J., Smith, A., Mackenzie, I., Thompson, S., Bal, I., Macharia, I., Mugwe, P., Okoth-
Olende, C., Oburra, H., &Wanjohi, Z., et al (1992).A prevalence study of ear problems in
school children in Kiambudistrict. Int J Pediatr Otorhinolaryngol. 33(3):197-205
Johnson, C.D. (2002). Hearing and immitance screening. In J. Katz (Ed.), Handbook of clinical
audiology (5th Ed., 481–493). Baltimore: Williams and Wilkins.
Kennedy, C.R., McCann, D.C., & Campbell, M.J. (2006).Language Ability after Early Detection
of Permanent Childhood Hearing Impairment. New England Journal of Medicine, 354,
2131-2141.
Kittrel. A.P., & Arjmand, E.M. (1997). The Age of Diagnosis of Sensorineural Hearing
Impairment in Children. Int. Journal of Pediatric Otorhinolaryngology, 40, 97-106.
University of Ghana                              http://ugspace.ug.edu.gh
43
Lü, J., Huang, Z., Yang, T., Li, Y., Mei, L., Xiang, M., Chai, Y., Li, X., Li, L., Yao, G., Wang,
Y., Shen, X & Wu, H (2011). Screening for delayed-onset hearing loss in preschool
children who previously passed the newborn hearing screening. Int J Pediatr
Otorhinolaryngol.75 (8):1045-9.
Mccarter, D.F., Courtney, AU. & Pollart, S.M. (2007). University of Virginia Health System,
Charlottesville, Virginia. Am Fam Physician. 75(10):1523-1528.
Mundy, M.R. (2001). The Chapel Hill–Carrboro (NC) schools: Hearing and middle ear screening
for preschool and school age children. In J. Roush (Ed.), Screening for hearing loss and
otitis media in children. San Diego, CA: Singular Thomson Learning.
National Institute of Health (1990).Noise and hearing loss.NIH Consensus Statement, 8(1), 1‐24
Noise: A review of human studies. In Axelsson (Ed), Scientific Bases of Noise-Induced
Roberts, J., Burchinal, M., & Zeisel, S (2002). Otitis media in early childhood in relation to
children’s school‐age language and academic skills. Pediatrics.696‐706.
Roland, P.S., Smith, T.L., Schwartz, S.R., Rosenfeld, R.M., Ballachanda, B., Earll, J.M., Fayad,
J., Harlor, A.D. Jr., Hirsch, B.E., Jones, S.S., Krouse, H.J., Magit, A., Nelson, C., Stutz,
D.R., & Wetmore, S. (2008). Clinical practice guideline: cerumen impaction.
Otolaryngol. Head Neck Surg. 139, S1–S21.
Rose, L.A., Andrew, S., Deborah, E. & Saravana, E., (2003). Pre-school hearing screening.
Pass/Refer rates for children enrolled in a head start program in Eastern North Carolina.
American Journal of Audiology. 16(1), 4-12.
Sarafraz, M. & Ahmadi, K.H. (2009).A practical screening model for hearing loss in Iranian
school-aged children. World J Pediatr. 5(1): 64-72.
University of Ghana                              http://ugspace.ug.edu.gh
44
Smith, A. (2003). Preventing deafness: An achievable challenge: The WHO perspective.
International Congress Series. 1240, 183-191.
Spivak, L. Datzell, L., Berg, A., Bradley, M., & Cacace, A (2000). The New York universal
newborn hearing screening demonstration project: Inpatients outcome measures. Ear and
Hearing.21, 92-103.
Silverman, S. et al (1994).Puretone Assessment and Screening of Children with Middle Ear
Effusion. J. Am Academy Audiology. 5(3) 173-82.
United Nations Children’s’ Funds (UNICEF) (2005).State of the world’s children, New York.
Oxford University Press.
Walker, J. J. et al (2013). Hearing Test and Screening in Young Children. American Family
Physician. 82 (1) 41 – 47.
Watkins, P.M. (2001).Neonatal screening for hearing impairment. Seminars in Neonatology.6,
501-509.
White, K.R. (1997). The scientific basis for newborn hearing screening. Early Hearing Detection
and Intervention (EHDI).Centers for Disease Control and Prevention. Atlanta, Georgia.
White, K.P. (2004). Early Hearing Detection and Intervention Programs: Opportunities for
Genetic Services. America Journal of Medical Genetics, 130(A), 29-36.
World Health Organization (WHO) (1999).Health Promotion: milestone on the road to a global
alliance .WHO fact sheet. No 171.Available at http://www.Int /inffs/en fact171.html
Yoshinaga‐Itano, C, Sedey, A., Coulter, D., & Mehl, A. (1998). Language of early‐ and
later‐identified children with hearing loss.Pediatrics.102: 1161–1171.
Yowhinaga-Itano, C & Apuzzo, A. (1998). Language of early- and later-identified children with
hearing loss. Pediatrics.102 (5):1161-71.
University of Ghana                              http://ugspace.ug.edu.gh
45
APPENDIX
University of Ghana                              http://ugspace.ug.edu.gh