Analysis and detection of binaural interaction in auditory evoked brainstem responses by time-scale representations.

The beta-wave of the binaural interaction component (BIC) in auditory evoked brainstem responses has been shown to be an objective measure of binaural interaction. However, a reliable and automated detection of this component capable of clinical use still remains a challenge. In this study, wavelet based time-scale representations of auditory evoked brainstem responses were investigated for the analysis of binaural interaction and for an automated detection of the beta-wave. Twenty normal hearing subjects with verified normal directional hearing and speech intelligibility in noise were included in our study. In all of these subjects, the BICs exhibited a characteristic concentration of energy in the time-scale domain which allowed for an automated detection of the beta-wave. Moreover, our study provides an explanation why the beta-wave is hard to detect for larger interaural time delays using time-scale entropy based arguments. It is concluded that time-scale representations of auditory brainstem responses are well suited for the analysis of binaural interaction and allow for an automated detection of the beta-wave.