The impact of electric hearing on children's timbre and pitch perception and talker discrimination

摘要

Present-day cochlear implant (CI) processing strategies typically remove the temporal fine-structure information in the stimulus waveform and preserve the temporal envelope, resulting in coarse spectral cues and poor frequency resolution. This degraded signal is sufficient for supporting perception of segmental features of speech in quiet, but is poorly suited for perception of those aspects of musical or spoken communication for which temporal fine structure is especially salient (Galvin et al, 2007; Limb and Roy, 2014; Looi et al, 2012; See et al, 2013). To what extent does the degraded representation in electric hearing (hearing through a CI) undermine accurate perception of several spectrally complex features of music and speech (i.e. timbre, pitch, and talker discrimination) in pediatric CI users? Are there experiential factors (e.g. acute vs. long-term exposure to electric hearing; age at time of testing, music instruction) and the characteristics of the auditory signal (e.g. timbre, pitch, talker discrimination) that have a significant influence on perceptual accuracy for spectrally complex music and speech sounds? These questions have implications for establishing realistic user expectations for pediatric CI users, as well as evaluating accuracy of research of using simulation methodology in predicting CI benefit.