Auditory threshold detection in Guinea pigs using chronically implanted electrodes and quasi auditory steady state responses.

Background/aim: This study aimed to compare electrophysiological hearing thresholds in guinea pigs exposed to intra-cochlear trauma using the continuous loop deconvolution averaging method (CLAD) and quasi-auditory steady state responses (QASSR).

Material and methods: Eight guinea pigs were implanted with electrodes at the lambda point. Intra-cochlear trauma was induced via electrode insertion. Hearing thresholds and amplitudes at 0.5, 1, 4, and 16 kHz were recorded using CLAD and QASSR methods. Recordings from the lambda electrode were compared with those from a conventional retro-auricular needle electrode.

Results: The lambda electrode demonstrated significantly lower mean auditory thresholds at all tested frequencies compared to the retro-auricular needle electrode in both trauma and non-trauma groups (P < 0.05). Amplitude comparisons revealed statistically significant differences at 1 kHz in the trauma group, and at 4 and 16 kHz in both trauma and non-trauma groups (P < 0.05).

Conclusion: The QASSR technique, coupled with chronic lambda electrode implantation, provides an effective method for estimating hearing loss induced by intra-cochlear trauma in guinea pigs.