Temporal integration in vowel perception

Abstract

Psychoacoustic research suggests that multiple auditory channels process incoming sounds over temporal windows of different durations, resulting in multiple auditory representations being available to higher-level processes. The current experiments investigate the size of the temporal window used in vowel quality perception using an acoustic priming paradigm with nonspeech and speech primes of varying duration. In experiment 1, identification of vowel targets was facilitated by acoustically matched nonspeech primes. The magnitude of this effect was greatest for the shortest (25 and 50 ms) primes, remained level at medium (100 and 150 ms) duration primes, and declined significantly at longer prime durations, suggesting that the auditory stages of vowel quality perception integrate sensory input over a relatively short temporal window. In experiment 2, the same vowel targets were primed by speech stimuli, consisting of vowels using the same duration values as those in experiment 1. A different pattern of results emerged with the greatest priming effects found for primes of around 150 ms and less priming at the shorter and longer durations, indicating that longer-scale temporal processes operate at higher levels of analysis.