Improving Clinical Practice for Babies with Hearing Loss
A study carried out by the Ladies in the Van.
Developing new hearing tests to better understand how well babies hear speech through their hearing aids.
Babies typically have a hearing check within the first days of life, meaning hearing loss can be diagnosed and hearing aids prescribed within just a few weeks.
We can’t reliably test a baby’s hearing by watching how they respond to sounds until they are at least 7 months old, and the test they have as newborns is not so good for older babies, nor for testing via hearing aids.
That means that for babies who are 3-7 months old, a new type of hearing test is needed to help understand how well these babies are hearing all the speech sounds needed to develop good language skills.
Researchers known as the Ladies in the Van travelled the UK in our Mobile Research Unit between 2016 and 2020. They used this new Cortical Auditory Evoked Potential (CAEP) test on over 100 babies with hearing loss.
Watch our video to find out more about the study.
What we did and our findings
We investigated different aspects of hearing loss in babies. Our findings have been published in research journals.
Below is a summary of what we did, with links to the full research papers.
New test sounds
The first thing the study team did was develop new types of sounds to use in the CAEP test (known as the ManU-IRU stimuli).
The sounds were designed so that hearing aids would treat them like speech and not background noise. They are also each focused on a specific pitch, so that we can learn about exactly which pitches babies can and can’t hear.
We developed the sounds and showed that they work well for testing via hearing aids.
- Research paper (Trends in Hearing): A Set of Time-and-Frequency-Localized Short-Duration Speech-Like Stimuli for Assessing Hearing-Aid Performance via Cortical Auditory-Evoked Potentials
New analysis method
We also investigated which are the best statistical tests to determine whether a CAEP test is positive (whether the result shows the sound could be heard) in a group of young adults.
We identified a novel way of analysing the data that improves the sensitivity of the test.
- Research paper (Ear and Hearing): Efficient Detection of Cortical Auditory Evoked Potentials in Adults Using Bootstrapped Methods
We have also done the same work looking at ways to analyse CAEP results from babies, and will publish our results soon.
Challenges of infant hearing aid use
We asked the caregivers taking part in our study how they were getting on with managing their babies’ hearing aids, what helped them, and what factors made hearing aid use more challenging.
This is really important, as we know that longer hours of regular hearing aid use mean better outcomes.
We found that daily hours of hearing aid use actually decreased later on in the first year of life. Caregivers often struggled with troubleshooting hearing aids, hearing aids whistling, distractions of other children in the home, difficulty getting into a routine, long waits for appointments, faulty hearing aids, and babies pulling hearing aids out.
Caregivers also offered solutions and tactics that have/might have helped them, including more information on what their baby can hear with/without aids, peer support, and information for relatives/other carers.
- Research paper (Ear and Hearing): Longitudinal Changes in Hearing Aid Use and Hearing Aid Management Challenges in Infants)
Listening skills in UK infant hearing aid users
Young babies with mild-moderate hearing losses tended to have listening skills on a par with babies with normal hearing.
However, as these babies got a little older, they tended to perform less well compared to babies with normal hearing.
Research paper (International Journal of Audiology): Longitudinal assessment of listening skills in UK infants with hearing aids using the LittlEARS® auditory questionnaire
How well does the CAEP test work?
The CAEP test, using the ManU-IRU stimuli:
- is acceptable to caregivers;
- takes an acceptable time to complete (around 24 minutes);
- is a sensitive test for measuring which sounds can be heard, when repeat recordings are taken into account, particularly for our mid-frequency stimulus;
- provides useful extra information to clinicians to support management of the hearing loss.
Results have been reported in the media, for example, in the Independent: New test could reassure parents their baby’s hearing aids are working.
This presents independent research funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) Programme (Grant Reference Number P B-P G-0214-33009).
The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.
Additional funding was provided by the Marston Family Foundation, William Demant Foundation, the Owrid Foundation, and NIHR Manchester Biomedical Research Centre.