Authors: Fauve Duquette-Laplante¹; Varghese Peter²; Christian Boyle¹; Ajay Raman³; Shivani Prabhu¹; Mridula Sharma¹
¹Flinders University; ²University of the Sunshine Coast; ³University of Queensland
Background: In older adults, the most common type of hearing loss is bilateral sensorineural, which impacts both audibility and auditory processing. Consequently, hearing aids that address audibility deficits often provide limited benefit in noisy settings. This study investigates the effects of mild-to-moderate hearing loss on listening in noise among older adults using a cortical speech tracking framework.
Method: Cortical speech tracking was measured in 13 older adults (mean age 74 years) using a temporal response function (TRF) framework. Participants listened to 15-minute podcasts in free field at 65 dB SPL in quiet and in the presence of 8-talker babble (+5 dB SNR). Testing included both unamplified and amplified (NAL-R formula) paradigms. Additionally, speech reception thresholds (SRT) were measured behaviorally using the ToLD-U test.
Results: Amplification significantly improved behavioral speech reception thresholds [F(1, 12) = 44, p < 0.001]. However, it did not improve the predictive accuracy of cortical tracking, which remained similar across quiet and noise conditions, regardless of amplification. Contrary to the initial hypothesis, hearing loss and noise did not significantly impact the predictive accuracy of speech features in this specific population.
Conclusion: These findings suggest that older adults with hearing loss can maintain cortical tracking of speech even in background noise, possibly by utilizing compensatory strategies such as language skills, low-frequency hearing, or selective attention. Despite high individual variability, the disconnect between behavioral SRT improvement and stable cortical tracking warrants further investigation. Ongoing data collection will include older adults without hearing loss to further clarify these mechanisms.
