Stapedial reflex and ears with high static acoustic admittance.

PURPOSE: To evaluate modified acoustic reflex diagnostic protocols for a group of individuals (n = 9) with high peak compensated static acoustic admittance (Y(tm)) tympanograms.

METHOD: A modified procedure designed to improve acoustic stapedius reflex threshold (ASRT) measurements in individuals with high-admittance tympanograms was employed in both an experimental and a control group. ASRTs were measured at 0.5, 1.0, and 2.0 kHz, ipsilateral and contralateral. Measurements were obtained within each condition for 7 ear canal pressures that were set to 0, +/-50, +/-100, and +/-150 daPa (relative to tympanometric peak pressure [TPP]).

RESULTS

Though measuring ASRTs at -50 daPa (relative to TPP) in the high-admittance and normal groups did not result in significantly better thresholds than at TPP, the absent reflex rate was reduced when the ear canal pressure was changed by -50 daPa during ASRT measurements.

CONCLUSIONS

Based on this sample, it is suggested that a patient presenting with high peak compensated static acoustic admittance (peak Y(tm) > or = 2.1 mmho) undergo ASRT evaluation with the ear canal pressure set to -50 daPa (relative to TPP).