The effects of acoustic modifications on the identification of familiar voices speaking isolated vowels

Abstract The aim of the present study was to examine the relative importance of various acoustic features as cues to familiar speaker identification for the vowel /a/. To this aim, a group of 20 speakers was recorded. The speakers' voices were modified using an analysis–synthesis system, which enabled analysis and modification of the glottal waveform, of the fundamental frequency, and of the vocal tract formants. Thirty listeners, very familiar with the speakers’ voices, had to identify the speakers in an open-set, multiple-choice experiment. The results suggest that on average, the contribution of the vocal tract features to the identification process is more important than that of the glottal source features. The exact shape of the glottal waveform was found to be of minor importance. Examination of individual speakers reveals that changes of identical features affect the identification rate of various speakers differently. This finding suggests that for each speaker a different group of acoustic features serves as the cue to the vocal identity.