Authors: Hamssika Sudhakar¹; Prashanth Prabhu¹
¹All India Institute of Speech and Hearing
Background: Misophonia is characterized by strong aversive emotional reactions to specific sounds. Frequency Following Response (FFR) provides insights into the subcortical neural encoding of sound, with contributions from brainstem structures, which may help explain the heightened reactivity to everyday auditory stimuli reported in misophonia. The present study aimed to investigate auditory encoding objectively using FFR in individuals with misophonia.
Method: Thirty participants were recruited and divided equally into two groups: a misophonia group (n = 15) and a control group (n = 15). Individuals with misophonia were identified using Schröder’s diagnostic criteria (2014), and severity was assessed using the Revised Amsterdam Misophonia Scale (AMISOS-R). FFR was recorded using a 40 ms /da/ stimulus, presented at 70 dB SPL via ER-3 insert earphones, binaurally. Offline analysis included identifying FFR peaks and extracting latency and amplitude values.
Results: The independent-samples t-test revealed a significant difference in the latency of peak O between the two groups. The offset peak was significantly delayed (p = 0.001) in the misophonia group compared to the control group. These findings are consistent with previous work suggesting delayed auditory neural processing at the brainstem level, potentially reflecting an underlying timing anomaly.
Conclusion: The results suggest a possibility of delayed subcortical auditory encoding of speech in individuals with misophonia. This aberrant neural timing at the brainstem level may reflect an underlying auditory processing anomaly that predisposes individuals with misophonia to disproportionate emotional and physiological responses to specific sounds.
