An acoustic comparison of nonlinguistic sounds to sentences spoken in American English.

Abstract

Acoustic characteristics of nonlinguistic (nonspeech) sounds (NLSs) were measured for duration and spectral variation, and compared to acoustic characteristics of spoken sentences (TIMIT database). The NLS, included samples produced by animal, human, mechanical, and natural sources. The acoustic comparison examined stoplike onsets, fricativelike intervals, vowel‐like intervals, and syllablelike variations in amplitude. The NLSs were identified by two groups of listeners: listeners with normal hearing and users of cochlear implants. Results of the listening tests have been reported previously by Inverso et al. (2007) and Inverso (2008). All of the NLSs were identified accurately by listeners with normal hearing, but not by the users of cochlear implants. The current analysis focuses on the ways in which the NLSs are similar to and other ways in which they are different from sentences spoken by a variety of talkers. It was found that speechlike variation in amplitude, both in terms of duration and event onset/offset, was a strong cue for listeners with cochlear implants; that is, NLSs that contained distinct events that were similar in duration and amplitude variation to syllables in speech were identified more accurately than ones that did not.