Subcortical Auditory Processing and Speech Perception in Noise Among Individuals With and Without Extended High-Frequency Hearing Loss

Purpose: The significance of extended high -frequency (EHF) hearing (> 8 kHz) is not well understood so far. In this study, we aimed to understand the relationship between EHF hearing loss (EHFHL) and speech perception in noise (SPIN) and the associated physiological signatures using the speech-evoked frequency-following response (sFFR). Method: Sixteen young adults with EHFHL and 16 age- and sex-matched individuals with normal hearing participated in the study. SPIN performance in right speech-right noise, left speech-left noise, and binaural listening conditions was evaluated using the Turkish Matrix Test. Additionally, subcortical auditory processing was assessed by recording sFFRs elicited by 40 -ms /da/ stimuli. Results: Individuals with EHFHL demonstrated poorer SPIN performances in all listening conditions (p < .01). Longer latencies were observed in the V (onset) and O (offset) peaks in these individuals (p <= .01). However, only the V/A peak amplitude was found to be significantly reduced in individuals with EHFHL (p < .01). Conclusions: Our findings highlight the importance of EHF hearing and suggest that EHF hearing should be considered among the key elements in SPIN. Individuals with EHFHL show a tendency toward weaker subcortical auditory processing, which likely contributes to their poorer SPIN performance. Thus, routine assessment of EHF hearing should be implemented in clinical settings, alongside the evaluation of standard audiometric frequencies (0.25-8 kHz).