The auditory tau and kappa effects for speech and nonspeech stimuli

Abstract

The tau effect, an effect of temporal intervals on the perception of spatial separation or sensory difference, has been observed in various sense modalities, including pitch bisection judgments in audition. However, systematic studies on the mechanism of the auditory tau effect have been rather scarce. In the present study, experiments were carried out using the AXB method to investigate the auditory tau effect on the pitch perception of pure tones (Experiment 1), the auditory tau effect on perception of the /e/-/i/, /iA/e/, /I/-/i/, and IM-lll continua (Experiment 2), and the kappa effect-an effect of sensory differences on the perception of temporal intervals-on the perception of pure tones and synthetic vowels (Experiment 3). The results demonstrated that the auditory tau effect occurs not only in the pitch perception of pure tones, but also in the phonetic perception of the fU-iil and /iA/I/ continua of synthetic vowels. The reverse pattern of results was obtained in the /e/-/i/ and /iA/e/ continua. The kappa effect was found both in the pitch perception of pure tones and in phonetic judgments of synthetic vowels. These findings suggest that the interaction between temporal interval and pitch (or phonetic) perception can be explained on the basis of the integration of forward and backward context effects, and that the auditory tau and kappa effects occur at an early stage of auditory information processing. © 1986 Psychonomic Society, Inc.