EarGenie hearing test for babies
How does hearing impairment in babies affect speech development?
Babies learn to speak by hearing speech.
So, not being able to hear the vital sounds needed in the early months of life means that speech development in babies who are deaf or hard of hearing can be delayed or permanently affected.
If the right management is not found in the first few months of life, these children never catch up with their peers, which affects their education, communication skills and future success in life.
The earlier that hearing issues are identified, and the baby provided with either a hearing aid or cochlear implant, the sooner they can start learning to speak, and the better language development will be.
What is the current situation with hearing tests for babies?
For many babies, the current newborn hearing tests can indicate how severe the hearing problem is, but do not give key information about whether the brain can discriminate between sounds.
Audiologists need vital information about whether a baby can discriminate between sounds to tune hearing aids or cochlear implants and optimise early intervention.
However, it is often necessary to wait until a baby is 9 months old or older before audiologists can determine if their hearing devices are helping them to hear the sounds they need.
This is because babies are too young to tell audiologists if they can hear sounds or discriminate between them.
Around 10% of hearing-impaired children have a condition called auditory neuropathy and for them the situation is much worse.
They may have to wait up to 2 years before audiologists can select the right device because existing tests do not provide the necessary information.
By this time, their language and communication skills are permanently affected.
Using light to assess hearing in babies
Researchers at the Bionics Institute are working on a new hearing test system called EarGenie, which will revolutionise hearing assessments for babies.
EarGenie uses light ( a technique called functional near-infrared spectroscopy or fNIRS) to measure the brain’s response to sounds.
A band wrapped around the baby’s head contains small light sources and light detectors.
When the brain responds to a sound there is a change in oxygen level which can be detected by EarGenie.
These changes indicate whether the baby has heard the sound; and also whether the baby can tell the difference between two different sounds, known as discrimination.
Eventually this technology will allow audiologists to tune hearing devices, such as hearing aids and cochlear implants, accurately from the very start, allowing babies to hear vital sounds and give them the best start in life.
Next steps for EarGenie
Our team has refined the EarGenie tests and have shown that they are more than 95% accurate in individual babies.
This means that the tests are accurate enough to help guide audiologists when they make important decisions about the best way to optimise the hearing of a baby.
We are undertaking a clinical trial to find out how useful the tests are for audiologists.
We are looking for both audiologists and infants with hearing impairment who want to be part of this trial.
We are currently building a prototype EarGenie that audiologists can use in clinics.
Our current research findings have been obtained using our research fNIRS system.
The prototype EarGenie will be clinic-friendly and have automatic analysis so the audiologist can run a hearing test and get the result in the same test session.
The new prototype EarGenie will be available for clinical trials in the later part of 2023.
These trials are an important step towards commercialisation of EarGenie, and from there to make EarGenie available to clinics worldwide.
Want to get involved?
For families with infants
To continue with our research and development, we need to test EarGenie on infants younger than 24 months old, both with and without hearing impairment in our East Melbourne testing centre.
If your child is under 24 months of age, please consider participating in this vital research. We are looking for babies who are hard of hearing (any type) as well as those without hearing impairment.
Your participation will involve a single visit to the Bionics Institute for an EarGenie test.
For audiologists
If you are an audiologist and work in a paediatric setting, you can participate in our current clinical trial.
We need more than 40 audiologists to participate.
You will be asked to provide online answers to clinical questions about individual (anonymised) infant data, and participation will only require about 10 minutes of your time several times a month
Team members:
Dr Julia Wunderlich, Ms Linty McDonald, Dr Darren Mao, Dr Demi Gao and Dr Gautam Balasubramanian.
More information for researchers
Speech discrimination assessment is a key component of the audiometric test battery because of its functional relevance and importance for device choice (e.g., hearing aid versus cochlear implant). However, there is currently no reliable and clinically feasible test (behavioural or objective) to measure speech discrimination in infants. The average age of diagnosis has been greatly reduced by the introduction of universal newborn hearing screening, meaning that new clinical tests, applicable to very young infants, are required. The absence of such tests means that for individual infants, the optimal choice of hearing device and its accurate programming can be substantially delayed by many months.
Researchers in the Bionics Institute are using fNIRS, a neuroimaging technique that is portable, relatively cheap, and clinical-friendly in sleeping infants to address this gap. Apart from its suitability for use in infants, two other features of fNIRS make it an attractive modality in infants compared to auditory evoked potentials. Firstly, fNIRS allows testing without interference from electrical artifacts, a particularly useful feature when assessing cochlear implant users. Secondly, fNIRS can be used in infants with auditory neuropathy, as it does not rely on neural synchrony.
The research has involved creating novel stimulation protocols and an automated response detection algorithm that has resulted in a test for speech sound discrimination with >95% accuracy. The team is now building a commercial EarGenie prototype for use in audiology clinics and are conducting a clinical trial to prepare for regulatory approval.
Publications
McKay, C., Wunderlich, J., Mao, D., Balasubramanian, G., Lee, O. W., Gao, D., & McDonald, L. (2023, June 20). A reliable, accurate, and clinic-friendly objective test of speech sound detection and discrimination in sleeping infants. https://doi.org/10.31234/osf.io/fbwcm
Lee, O. W., Mao, D., Wunderlich, J., Balasubramanian, G., Haneman, M., Korneev, M., & McKay, C. M. (2023). Two independent response mechanisms to auditory stimuli measured with fNIRS in sleeping infants. Preprint available at Research Square [https://doi.org/10.21203/rs.3.rs-2493723/v1].
Mao D, Wunderlich J, Savkovic B, Jeffreys E, Nicholls N, Lee OW, et al. Speech token detection and discrimination in individual infants using functional near-infrared spectroscopy. Scientific Reports. 2021;11(1):24006. https://doi.org/10.1038/s41598-021-03595-z
Lee, O.W., Mao, D., Savkovic, B., Wunderlich, j., Nicholls, N., Jeffreys, E., Eager, M., Korneev, M., McKay, C.M. The Use of Heart Rate Responses Extracted from Functional Near-Infrared Spectroscopy Data as a Measure of Speech Discrimination Ability in Sleeping Infants. Ear and Hearing, 2023 Jan 14. doi:10.1097/AUD.0000000000001325. Online ahead of print.
Peng, T., Esmaelpoor, J., Mao, D., Lee, O.W., Balasubramanian, G., Wunderlich, J., McKay, C.M. A Parametric Model for Characterizing Time-Variant Single Trials of Block-Design fNIRS Experiments. by 45th Annual International Conference of the IEEE Engineering in Medicine and Biology Society July 24-28, 2023, ICC Sydney, Australia.
