Changes in F2−F1 as a voicing cue

Abstract

The interaction between formant transitions and vowel length was measured with respect to syllable final voicing distinctions. A synthesized ad VC token of 360 ms was edited in 5-ms intervals from either side, onset or offset, so that 260 ms were preserved. Ten subjects were asked to make final voicing judgments for the words ‘‘odd’’ and ‘‘ought’’ ([ad] vs [at]) when hearing the 20 edited tokens. Each token was presented five times, randomly, for a total of 1000 judgements. Results showed an overwhelming number of voiced responses when the entire offset was preserved and symmetrical voiceless results with the deletion of offset. A follow-up experiment utilized a similarly synthesized token of 460 ms. The results when adding 100 ms onto the vowel were insignificantly different than the results acquired for formant transitions, suggesting the latter are a more important cue for syllable final voicing distinctions. These findings contradict previous vowel length conclusions [L. J. Raphael, J. Acoust. Soc. Am. 51, 1296–1303 (1972)] and further suggest that in addition to F1 [V. Summers, J. Acoust. Soc. Am. 84, 485–492 (1988)], F2 transitions are also an important cue to final voicing distinctions in low vowel contexts.