Perceptual (ir)relevance of the envelope features: steady time versus decay time

Rise (± interrupted) and decay time (± checked) of speech sounds have often been proposed as distinctive features with perceptual correlates. Production data will be presented from Hausa, a Chadic language from Africa, suggesting that the prepausal pure vowel short-long contrast is exclusively characteristic by decay-time differences. In the corresponding perception experiment steady time and decay time were orthogonally varied, observing equal ranges and stepsize, and amply covering the parameter space found in the production experiment. Results indicate that decay time does not contribute more to the contrast than steady time. It will be argued that the Jakobson, Fant, and Halle feature (± checked) is without perceptual correlates in the case of vowels; an explanation will be sought in the poor auditory discriminability of rise and decay time phenomena [V. J. J.P. van Heuven and M. P. R. van den Broecke, J. Acoust. Soc. Am. 65, 1308–1315 (1979); M. P. R. van den Broecke and V. J. van Heuven, preceding abstract]. [Work supported in part by the Netherlands Organisation for the Advancement of Pure Research, Z. W. O.]