The Auditory Kappa Effect in a Speech Context

Results of a perception experiment show that the size of the pitch difference between spoken words on either side of a pause affects perception of pause duration, demonstrating that the auditory kappa effect can obtain in speech materials. The auditory kappa effect is an illusion whereby, in a sequence of tones and intervening silent intervals, the perception of the duration of the silent intervals is influenced by the relative pitch of the tones, and has previously been demonstrated only using musical or simple (sinusoidal) tones. This study extends these findings to spoken language materials, suggesting that the influence of pitch on the perception of speech timing needs to be further examined. The results of this study, along with studies showing the complex effects of dynamic pitch on perceived duration, are discussed with respect to implications for phonetic measures of prosodic events, such as relative boundary size and syllable lengthening.