The Hearing House
Student research into speech-in-noise testing could contribute to changing practices in audiology
University of Auckland Audiology Masters’ student Gaby Surja had a major career change two years ago when she decided she wanted to do something that really made a difference to people’s lives.
The former transport engineer, who spent eight years working on major traffic infrastructure projects in and around Auckland, traded her hard hat for an audiometer and has never looked back.
She says audiology ticked all the right boxes – the nature of the work, the work-life balance it offers, the interaction with people, and the fact that the service could be tailored to fit the needs of clients and their whānau.
In choosing her thesis topic, Gaby sought the advice of her supervisor and Hearing House Clinical Director for audiology and rehabilitation, Dr. Holly Teagle, who encouraged her to look into improving and developing clinical practices that could reflect real-life challenges for clients.
The Hearing House works closely with the University of Auckland Audiology programme, providing clinical experience placements for students and collaborating on research.
Gaby’s chosen topic – Speech Perception in Noise Assessment – examines an area that is not currently a standard part of audiology testing in New Zealand, but Gaby is hoping her research might change that.
Most testing is done without background noise, which Gaby says isn’t a good representation of what we come across in real life – think noisy streets, busy cafes, and loud parties.
“In general, speech-in-noise tests are more realistic for estimating an individual’s real-life listening abilities compared to speech tests in quiet,” she says.
“However, the barriers need to be understood and addressed before speech-in-noise testing is accepted as an industry standard.”
Gaby is due to start a full-time role with Dilworth Hearing in Remuera and Takapuna in March once she’s submitted her thesis, but she views her time spent at The Hearing House as her most formative period. At first, she found academic research challenging after her years spent on busy design and construction projects but found her happy place when she discovered clinical application and dealing with people.
“Audiology is a well-balanced mix of science, technology, and people,” she says. “The highlight of my research has been the human interaction.”
Gaby says that poor speech perception in noise is one of the most common complaints of adults with sensorineural hearing loss – or loss caused by damage to the inner ear. She says that an understanding of a person’s speech perception in noise is crucial for deciding on an appropriate rehabilitation strategy, including the fitting of hearing devices such as cochlear implants and hearing aids.
In addition, she says the performance of hearing devices in noise is largely tested in controlled laboratory conditions, and not validated in realistic acoustic environments.
This can lead to persistent complaints of hearing difficulty in noisy situations, despite the use of a hearing device.
A hearing loss assessment that reflects everyday speech, modified to suit Kiwis
The Arizona Biomedical (AzBio) sentence test is a speech-in-noise test that was originally developed in the US as speech recognition assessment for cochlear implant recipients. To capture the nuances of the New Zealand accent, a Kiwi version of the test was recently recorded.
The construction and recording of the NZ AzBio sentences are intended to reflect that of conversational speech in everyday listening environments, as opposed to clear speech.
Consequently, the NZ AzBio sentences are more difficult and lead to comparatively lower scores than other tests. These scores may more accurately reflect a person’s ability to hear and understand in the real world.
Using the NZ AzBio sentence test, Gaby conducted a speech-in-noise assessment with a group of nearly 30 adults – half with normal hearing and half with hearing loss. Gaby’s results will be analysed early this year in order to assess the validity and reliability of the Kiwi version of the test -- an essential step in introducing the test to the range of audiology measurements available in New Zealand.
Removing the barriers to performing speech-in-noise testing
In addition, as part of her research, Gaby surveyed 95 audiologists to better understand their perception and use of speech-in-noise testing in New Zealand audiology clinics.
Her results showed that a vast majority (98%) of audiologists think that speech-in-noise testing is important for diagnostics, counselling and rehabilitation, and yet only half (50%) use it more
than 20% of the time in their current practice.
Gaby says that initial results show that the biggest barriers for using speech-in-noise testing appear to be lack of time, lack of guidance or experience, and the fact that speech-in-noise testing is not currently included in the NZAS Best Practice Guidelines for Speech Audiometry and Hearing Aid Fitting.
She hopes that her findings could add further weight to the move to have speech-in-noise testing adapted as best practice in New Zealand – and help create a better understanding and more realistic picture of how people with hearing loss cope in our noisy world.