Abrupt ITD changes elicit auditory-evoked responses with distinct latencies

Evidence

Direct measures of ITD sensitivity, attributed to multiple generator sites in the thalamus and auditory cortex (Picton et al. 1974 ; Hari et al. 1980 ; Näätänen and Picton 1987 ; Liégeois-Chauvel et al. 1994 ), have been demonstrated in auditory-evoked ‘P1-N1-P2’ responses, with abrupt changes in either the ITD (e.g. McEvoy 1991 ), or the interaural correlation of a noise (e.g. Chait et al. 2005 ), eliciting responses with typical latencies of 50, 100, and 175 ms, respectively. Although these studies demonstrate the capacity to assess binaural processing of interaural temporal information, they provide for only a relatively crude measure of ITD sensitivity, comparing, for example, EEG responses to diotic (identical) sounds at the two ears with responses to sounds that are statistically independent at the two ears. A more refined measure of ITD sensitivity would provide the possibility of assessing neural mechanisms of binaural processing in the human brain, aiding bilateral fitting of CIs in order to maximise binaural benefit. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2954

Categorization

• DEFINE: Defines the P1-N1-P2 evoked-response complex and how ITD changes elicit it, and clarifies the diotic vs statistically-independent comparative method.