A model of the perception of concurrent vowels at short durations

The perception of double vowel stimuli has previously been modelled on the basis of determining the pitch of the component sounds, using this information to segregate frequency channels which comprise each of the sounds, and then using a “vowel” template to identify the stimulus. Such models fail to adequately account for the human ability to distinguish vowels with the same fundamental frequency, or the effects of vowel inharmonicity, and have difficulty in explaining the results of experiments using short duration stimuli. The model we describe is based on the connectivity of the thalamocortical system and shows how a competitive recognition process and topdown suppression of the dominant vowel can lead to the identification of both vowels even in the absence of pitch grouping cues. This model provides a novel explanation for the perception of double vowel stimuli and is consistent with results showing the dependence of the phenomenon on stimulus duration