Perceptual discrimination of rise and decay time in speech‐ and nonspeech signals

Abstract

In a number of languages, differences in the decay time of vowels have been claimed to contribute to the perception of phonemic contrasts. In contrast with many other acoustic parameters relevant to speech perception, the perceptual acuity for abruptness phenomena has hardly been subjected to systematic psychophysical investigation. Previous experiments [V. J. J.P. van Heuven and M. P. R. van den Broecke, J. Acoust. Soc. Am. 66, 1308–1315 (1979)] have demonstrated that the JND is about 25% for rise and decay time differences in tone and noise bursts. Further experiments on vowel‐like signals seemed to demonstrate a superior accuracy for offsets as compared to onsets. However, interaction of these offsets with overall duration may have played a role. These experiments have been replicated in order to create full comparability of rise‐ and decay‐time signal conditions with respect to overall signal duration. Results indicate that perceptual acuity for rise and decay time in complex harmonic signals, including vowel‐like sounds, is essentially symmetrical and in the same magnitude of those earlier established for tone and noise bursts. Data will be presented and implications with respect to our earlier findings will be discussed.