Binaural interaction in auditory brain stem responses: parametric studies

The effects of click stimulus presentation rate, spectrum, and polarity on binaural interaction in auditory brain stem responses (BI/ABR) were observed in guinea pigs and in normal-hearing human adults. The effects of repetition rate on the BI/ABR in both species were similar to those seen in ABRs. Six of 16 human subjects showed an unusual "early BI" only at high click intensity and high repetition rates; this is probably due to acoustic reflex effects. Animal data from stimulus spectrum experiments suggest a mid-to-high frequency dependence of the BI/ABR, while human data are less clear. Results are discussed relative to suggested recording strategies for the BI/ABR.