EXPLORING UNILATERAL HEARING LOSS IN CHILDREN
Recent insights on early behavioural assessments and progression.
BY ANGELA WONG, STACEY MILNER AND DR VICKY ZHANG
Universal Newborn Hearing Screening (UNHS) programs have played a vital hearing loss (UHL) during infancy, in its recorded prevalence. Although intervention for optimal developmental outcomes, clinical management of UHL still presents several challenges its audiological characteristics and evidence-based information regarding target population.
Obtaining accurate, reliable, earfacilitate timely intervention as early as possible could be one of the biggest challenges for children with UHL. They must not only tolerate the use of insert earphones or headphones during the testing, but also need to cope with
testing more complex. Other common factors such as the child’s age, cooperativeness and limited
testing reliability. Currently, there is limited information available on when
for the impaired ear.
we can obtain reliable behavioural hearing levels for the impacted ear in children with UHL. Additional challenges include understanding the prevalence of progressive hearing loss in children with UHL and identifying indicated that a considerable proportion of children with UHL are one or both ears1,2 but the reported percentage of occurrence varies across studies. This inconsistency
loss used, age ranges of the children, measurement methods, follow-up
hearing loss under investigation. The factors contributing to progressive hearing loss in children with UHL are
Due to these challenges, we conducted analyses on a subgroup of children participating in an ongoing NAL project, ‘Children with Unilateral Hearing Loss study’ (CUHL study). The aim was to provide evidence on when a reliable behavioural audiogram could be obtained for children who have congenital UHL, and how their hearing changes over time. This article summarises our recent published 3, and we hope it helps clinicians better manage children with UHL by identifying any hearing
adjustments to intervention strategies accordingly.
1. Clinical notes marked as reliable results.
2. Must have measured thresholds at least at one lower (0.5 or 1 kHz) and one higher (2 or 4 kHz) frequency.
3. Must include masked air conduction and bone conduction thresholds when required.
audiogram obtained?
The report includes the analysis of a sample of 91 children who had: (1) a diagnosis of congenital UHL; thresholds estimated from electrophysiological testing at diagnosis; and (3) reliable behavioural audiograms performed at Hearing Australia in early childhood with at least one low audiogram is shown in the green box below.
The results showed that although the mean age at diagnosis of the sample was 2.1 months old, for approximately half of the children (n=43, 47.3%) the
had not been obtained for the impaired ear until after 3 years of age. Hearing Australia’s national paediatric clinical
should be obtained by 18 months of
reliable behavioural audiogram for children with UHL was 3.0 years (Figure 1).
perspectives of clinical paediatric audiologists in an online survey completed by audiologists at Hearing Australia3. Most respondents believed that a behavioural audiogram for individual ears could be reliably measured before 2 or 3 years of age for children with UHL. The potential reasons for this discrepancy could be related to clinicians’ opinions on the clinical management of individual children and the prioritisation of
other clinical needs or activities for
For example, in cases of children with severe to profound hearing loss or absence of an auditory nerve in one ear, clinicians tend to focus on assessing hearing in the normal ear and middle ear status. Similarly, this also applies to children with unilateral microtia or atresia as the hearing not impact device settings.
We also explored several potential factors that may contribute to the delay in obtaining reliable behavioural audiograms, such as demographic characteristics, presence or absence variables (e.g. degree of hearing loss at diagnosis, ongoing middle ear problems in the impaired ear, and children’s behavioural issues (e.g. loss or intolerance of earphones). Among all these variables, we found that cooperative behaviour from the child and the presence of ongoing middle ear issues in the impaired ear were the age.
Children with middle ear issues tended to have a greater number of appointments, providing them with more hearing testing opportunities at earlier ages, which resulted in more reliable test results at an earlier age. However, ongoing middle ear issues
reliable behavioural audiogram due
or the need for medical recovery from
outside periods of temporary middle ear dysfunction, and meeting other criteria, were considered as reliable for further analysis in this study. This exclusion may underestimate the age at which reliable audiograms could be obtained, as temporary middle ear dysfunction may not always impact hearing thresholds or diagnostic
this report only accounted for 11% of the total variance in age at behavioural audiometry. Additional research is needed to identify and gain a deeper understanding of the various factors contributing to delays in obtaining
particular, the attitudes of clinicians and parents or caregivers towards management of UHL in young children may be also worth investigating.
Understanding these perspectives will provide insights into how decisions are
made regarding audiological follow-up appointments, the prioritisation of clinical activities, and the perceived
audiograms. This information can help develop targeted strategies to address challenges and ensure children with UHL receive timely and comprehensive hearing habilitation.
Did hearing change from reliable audiogram?
When comparing the hearing
reliable behavioural audiogram to the baseline hearing thresholds at diagnosis, this study adopted two 3 , which are shown in the green box below.
of children experienced hearing deterioration rather than improvement
children diagnosed with congenital UHL experienced a hearing deterioration between the initial diagnosis and their 1, Figure 2). This deterioration was
a high proportion of these children (73.2%) experienced a deterioration in the degree of hearing loss from mild to severe to profound (Figure 2). Notably, there were more instances of hearing changes—either deterioration
Our analyses also demonstrated variations in the proportion and the clinical characteristics of children with hearing threshold changes of progressive hearing loss. When average thresholds) was applied, only
26% of children in the sample were
deterioration and around 2% showed improvement in the hearing levels, while a majority (71.4%) had stable hearing between the two measurement points. This suggests that adopting
deterioration may underestimate the proportion of children experiencing hearing changes, which could have a direct impact on management decisions.
Additionally, for the children with abnormal auditory nerves, atresia/ microtia, CMV, LVAS and syndromic hearing loss), it was found that most children with absent or abnormal auditory nerves, CMV and LVAS experienced further deterioration
2 showed consistent numbers of causes. Syndromic hearing loss didn't
2. Children born with atresia and/
underestimate the proportion of children that experienced hearing changes.
Clinical implications and conclusion
The study's strength lies in its focus on children diagnosed with congenital UHL through UNHS, which allows for a direct comparison between initial hearing thresholds from electrophysiological
behavioural audiogram. These are both considered gold standard tests for threshold estimation and measurement
Hearing Australia’s adherence to a nationally standardised clinical protocol, ensuring a consistent and reliable assessment methodology. The well-established diagnostic protocols in audiological diagnostic hospitals/ centres across Australia further reinforce the study's methodological practice strives for an early intervention goal of 1–2–3 (screening by one month old, diagnosis by two months old, and intervention by three months old)4,
in obtaining timely behavioural audiograms for children with UHL to ensure continued optimal intervention
Figure 2/ the 3FAHL (0.5, 1 and 2 kHz) of the behavioural in the 3FAHL.
and management. The observed delays suggest the need for additional strategies and resources to achieve the desired early intervention goal. loss, either in one or both ears. The
monitoring hearing threshold levels after diagnosis for timely intervention and appropriate management. Changes in hearing thresholds have adjustments and overall developmental
aetiological information. Overall, the closely monitoring hearing loss after initial diagnosis to ensure optimal interventions are implemented at the earliest age for children with UHL.
References
1. Barreira-Nielsen C. et al. (2016). Progressive hearing loss in early childhood. Ear Hear. 37(5):e311–21.
unilateral hearing loss in childhood: A 20-year view of hearing characteristics, and audiologic practices before and after newborn hearing screening. Ear Hear. 35(1):10–18.
with hearing progression in children with UHL still inconclusively understood
Close collaboration with ENT specialists addressing this challenge, as it could
3. Zhang V.W. et al. (2023). Audiological characteristics of children with congenital and change of hearing loss. Front Pediatr. 11:1279673.
Year 2019 Position Statement: Principles and guidelines for early hearing detection and intervention programs. J Early Hear Detect