Correlations between hearing thresholds and caloric responses among a heterogeneous sample of dizzy patients

Auditory and vestibular function were compared in a heterogeneous sample of dizzy patients (N = 52). Hearing thresholds for the conventional audiometric frequencies were measured for each patient and parceled into two frequency ranges, 0.25-1 kHz and 2-8 kHz. Hearing thresholds also were measured for each patient over an extended high-frequency range that included the frequencies 10, 12, and 14 kHz. Bithermal caloric responses for these patients were available and were grouped for unilateral weakness (UW) or no unilateral weakness (NOUW). Hearing thresholds ipsilateral to the side of unilateral weakness (UW) yielded significant (p less than .05) modest correlations (r = .39-.52) with UW for all three audiometric frequency ranges (N = 35). These findings do not suggest a strong tonotopic relation between the audiometric and UW data. Hearing thresholds for the frequency range 10-14 kHz, but not for the conventional audiometric frequencies, correlated with slow-phase eye velocity (SPV) when SPV was averaged across the four caloric conditions for each of 17 NOUW patients. The latter finding indicates a subtle trend for eye velocity to increase as a function of increasing hearing threshold.