Duplex perception of cues for stop consonants: Evidence for a phonetic mode

When the (vocalic) formant transitions appropriate for the stops in a synthetic approximation to spa] or sta] are presented to one ear and the remainder of the acoustic pattern to the other, listeners report a duplex percept. One side of the duplexity is the same coherent syllable (spa] or sta]) that is perceived when the pattern is presented in its original, undivided form; the other is a nonspeech chirp that corresponds to what the transitions sound like in isolation. This phenomenon is here used to determine why, in the case of stops, silence is an important cue. The results show that the silence cue affects the formant transitions differently when, on the one side of the duplex percept, the transitions support the perception of stop consonants, and when, on the other, they are perceived as nonspeech chirps. This indicates that the effectiveness of the silence cue is owing to distinctively phonetic (as against generally auditory) processes.