The role of short-term and long-term auditory storage in processing spectral relations for adult and child speech

Abstract

The processes involved in the perception of spectral change between the nasal murmur and the vocalic transition for speakers of different ages were assessed before and after disruption of the variation in spectra between these elements. Three children, aged 3, 5, and 7, and an adult female and male produced consonant-vowel (CV) syllables consisting of either [m] or [n] followed by [i] or [u]. In one condition (spectrally noncontiguous), the acoustic information surrounding the region of spectral change was digitally removed and in another condition (spectrally contiguous) this portion of the signal was retained. In both of these conditions, intervals of silence ranging from 0 to 2000 ms were inserted between 50-ms segments of murmur and vocalic transition. These gap duration conditions were then presented to adult listeners for the identification of the nasal. Across speakers, the results for the spectral contiguous condition support a primary mechanism in the perception of spectral relations that is mediated by processes within short-term auditory memory, but the results for the spectral noncontiguous condition revealed little consistent support for either short-term or long-term memory processes.