Can Electrocochleography Predict Pure Tone Thresholds Without Correction Factors?

BACKGROUND

Electrocochleography (EcochG) is a valuable method for determining frequency-specific objective hearing thresholds. While pure tone audiometry (PTA) is the gold standard, it can be inconclusive in certain populations, such as infants and non-responders. Auditory brainstem response is the primary electrophysiological test for threshold estimation in these groups. However, EcochG offers the advantage of closer field measurements, making it a promising alternative. This study compares PTA-based subjective thresholds with EcochG-derived objective thresholds in patients with varying degrees of hearing loss. METHODS: Participants consisted of individuals with both normal hearing and varying degrees of hearing loss. 0.5, 1, 2, and 4 kHz tone-burst stimuli and click stimuli were used to measure the latency and amplitude of action potentials (APs) using extra-tympanic electrodes. The AP component of the EcochG response was used as the primary measure for estimating hearing thresholds and was compared with PTA data. RESULTS: There is a strong correlation between 0.5, 1, 2, and 4 kHz pure tone thresholds (PTTs) and EcochG thresholds of the same frequencies (P < .001). Also, there is a strong correlation between click stimulus and the 4-frequency pure tone average (P < .001). The results of the linear regression analysis showed that the 0.5, 1, 2, and 4 kHz PTTs can be predicted using EcochG. Electrocochleography with click stimuli can also predict PTA of 4 frequencies. CONCLUSION: Using the EcochG test, hearing thresholds can be estimated without the need for a correction factor according to our results.