Early indicators of noise injury
The overarching aim of this study was to understand why some adults in their mid-years despite having normal hearing test results, report greater than expected difficulty understanding speech in noisy environments. The study primarily focused on whether noise exposure, thought to lead to loss of connections between the cochlea and auditory nerve fibres (cochlear synaptopathy) reduces the ability to hear and communicate. It also investigated whether musical training counteracts any noise exposure effects and potentially improves the ability to understand speech in noise. Additionally, the study sought to gain a better understanding the experiences and impacts of these hearing difficulties on communication.
The study results suggested that multiple factors contribute to the ability to understand speech in noisy environments. There is considerable individual variation in performance among listeners with normal or near-to-normal hearing test results but this is not related to levels of lifetime noise exposure. Other auditory and cognitive factors, such as extended high-frequency hearing (frequencies above those currently tested clinically), working memory and attentional skills, appear to be important for understanding speech when listening conditions are challenging. The biggest impact on participants who reported the most difficulty understanding speech in noise were avoidance of social situations, listening fatigue, inconvenience, and self-consciousness
The results of this work have been presented at local and international conferences, and published in peer-reviewed academic journals.
- Yeend I, Beach EF, Sharma M and Dillon, H (2017) The effects of noise exposure and musical training on suprathreshold auditory processing and speech perception in noise. Hearing Research, 353, 224-236. doi.org/10.1016/j.heares.2017.07.006
- Valderrama JT, Beach EF, Yeend I, Sharma M, Van Dun B, Dillon H (2018) Effects of lifetime noise exposure on the middle-age human auditory brainstem response, tinnitus and speech-in-noise intelligibility. Hearing Research, 365, 36-48. doi.org/10.1016/j.heares.2018.06.003
- Yeend I, Beach EF, Sharma M (accepted, 2018) Working memory and extended high-frequency hearing in adults: diagnostic predictors of speech-in-noise perception. Ear and Hearing, doi.org/10.1097/AUD.0000000000000640
- Beach, EF, (2018) Hidden hearing loss in humans: cochlear synaptopathy is superseded by cognitive effects when listening to speech in noise. ENT & Audiology News, 27(1):84-85.
- Bramhall N, Beach EF, Epp B, LePrell C, Lopez-Poveda E, Plack C, Schaette R, Verhulst S, Canlon B et al (2019) The search for noise-induced cochlear synaptopathy in humans: Mission impossible? Hearing Research, 377, 88-103. doi.org/10.1016/j.heares.2019.02.016