This study explores the value of fricative duration in the perception of voicing in Spanish sibilants. Natural speech forms containing [s] in a vowel-consonant-vowel (VCV) context were recorded by a native speaker of Argentine Spanish. The middle portion of the frication noise of these samples was abbreviated in three steps over a 120 ms range by digital editing techniques. Results of a listening test in which the voicing feature was to be identified indicate that shortening the duration of fs] produced a significant shift in perception towards [z]. This perceptual effect concurs with acoustic data observed here and reported in the literature that reveal a marked separation in the durational range of these two sounds. The experiment demonstrates a direct method for assessing non-contrastive sounds in a language given listener awareness of salient regional speech habits. The interaction of fricative duration and the perception of voicing in sibilants evidenced here is consistent with the patterning of these sounds in similar historical and synchronic data.
Bibliographic reference. Widdison, Kirk A. (1995): "The perception of voicing in Spanish sibilants", In EUROSPEECH-1995, 2289-2292.