[Examination of binaural signal processing in normally hearing subjects using electrophysiological and psychoacoustical measurements].

BACKGROUND AND OBJECTIVE

At present, only a small number of validated, clinically usable methods for the assessment of binaural hearing capabilities exist. A proposed electrophysiological measure is the registration of the brainstem-based binaural difference potentials (BDP).

PATIENTS/METHODS: The BDP is calculated as the difference between the binaurally evoked registration and the sum of the two monaural registrations. Detection and stability of the BDP were examined in 24 normally hearing adults within the framework of conventional registration of auditory brainstem responses. Furthermore, the influence of interaural time differences (ITD) on the BDP was determined. In addition, lateralization of the subjects was assessed using a psychoacoustical method.

RESULTS

The components of the BDP could be detected in almost all of the subjects. Moreover, they showed sufficient test-retest reliability. The impact of ITD,which causes lateralization of the stimulus,was clearly detectable for the latencies and the amplitudes of the BDP.

CONCLUSIONS

Binaural difference potentials, which are easily and reliably detectable reveal a relationship to the outcome of psychoacoustical assessment of lateralization and have the potential to provide a measure for binaural hearing capacity.