Ipsilateral and contralateral recordings of auditory brainstem responses to monaural stimulation.

The developmental changes of the ipsilateral and contralateral auditory brainstem responses (ABRs) were studied in 105 normal infants and children. In both ipsilateral and contralateral recordings, the peak and interpeak latencies shortened with increasing age, while the amplitudes of wave V had a tendency to become higher. Contralateral ABR amplitudes were always smaller than those of ipsilateral ABRs. In the contralateral recording, wave I was absent and the contralateral wave II and wave III complex began to separate after birth (25%); separation percentage reached 80-100% at 7 months of age. Our results suggest that the contralateral recording of ABRs is a useful measure of developmental changes in infant auditory pathways.