Objective measurement of high-level auditory cortical function in children

Objective: This study examined whether the N2 latency of the cortical auditory evoked potential (CAEP) could be used as an objective indicator of temporal processing ability in normally hearing children. Methods: The N2 latency was evoked using three temporal processing paradigms: (1) differences in voice-onset-times (VOTs); (2) speech-in-noise using the CV/da/embedded in broadband noise (BBN) with varying signal-to-noise ratios (SNRs); and (3) 16. Hz amplitude-modulated (AM) BBN presented (i) alone and (ii) following an unmodulated BBN, using four modulation depths. Thirty-four school-aged children with normal hearing, speech, language and reading were stratified into two groups: 5-7 years (n= 13) and 8-12 years (n= 21). Results: The N2 latency shifted significantly and systematically with differences in VOT and SNR, and was significantly different in the two AM-BBN conditions. Conclusions: For children without an N1 peak in the cortical waveform, the N2 peak can be used as a sensitive measure of temporal processing for these stimuli. Significance: N2 latency of the CAEP can be used as an objective measure of temporal processing ability in a paediatric population with temporal processing disorder who are difficult to assess via behavioural response.