Category interaction and stimulus effects in the perception of synthetic liquid+stop clusters.

Abstract

There are numerous studies of the perception of English stops in the syllables /arga, alga, arda, alda/ [e.g., A. Lotto and K. Kluender, Percept. Psychophys. 60, 602–619 (1998)]. Listeners give more /-da/ responses after /ar-/ syllables. There is controversy over the degree to which this effect involves general auditory contrast rather than phonetic context. The present study uses a two-dimensional continuum of 49 stimuli composed by crossing a seven-step /al-/ to /ar-/ series with a seven-step /-da/ to /-ga/ series. The variation in stimulus properties is localized to F3 only for both VC and CV stimuli. Listeners (n = 34) responded with all four categories. Results show clear phoneme level context effects. Ambiguous VC stimuli near the /al/-/arr/ boundary show significantly more /da/ responses in cases where the VC is heard as /ar/. This pattern is consistent with what has been called a diphone bias effect [T. Nearey, J. Acoust. Soc. Am. 101, 3241–3256 (1997)]. Surprisingly, for these stimuli, evidence for more continuous tuning of the /da/-/ga/ boundary by preceding l/r is quite weak. Thus, in this experiment, phonetic effects appear to dominate auditory contrast effects.