Perceptual equivalence of acoustic cues that differentiate /r/ and /l/.
The perceptual effects of orthogonal variations in two acoustic parameters which differentiate American English prevocalic /r/ and /l/ were examined. A spectral cue (frequency onset and transition of F2 and F3) and a temporal cue (relative duration of initial steady state and transition of F1) were varied in synthetic versions of "rock" and "lock." Four temporal variations in each of ten stimuli of a spectral-cue continuum were generated. Phonetic identification and oddity discrimination tasks with the four series showed systematic displacement of perceptual boundaries and discrimination peaks, thus reflecting a trading relation between the two cues. The perceptual equivalence of spectral and temporal cues was investigated by comparing the accuracy of discrimination of three types of stimulus comparisons: phonetically facilitating two-cue pairs, one-cue pairs, and phonetically conflicting two-cue pairs. As predicted, discrimination accuracy was ordered: Facilitating cues greater than one-cue greater than conflicting cues, indicating that perceivers discriminated on the basis of an integrated phonetic percept.
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception; D004192:Discrimination, Psychological; D005260:Female; D006309:Hearing; D006801:Humans; D008297:Male; D013060:Speech; D013997:Time Factors