Event overview
A lecture by Simon Makin, who is based at the University of Reading.
Abstract:
Typical listening situations consist of both multiple sound sources and numerous reflecting surfaces, so each sound is accompanied by a multitude of delayed, attenuated copies. This “reverberation” reduces speech intelligibility by masking later arriving portions of the direct sound and degrades the information conveyed by a sound’s temporal envelope. Further, the frequency response of any acoustic environment is typically not flat, creating spectral distortion. But reverberation is not always detrimental. It creates sensations of spaciousness, important in areas like architectural acoustics and music technology. Also, in the case of complex sounds such as speech, early reflections perceptually “fuse” with the direct sound, which can lead to an increase in effective SNR. Moreover, work in the Reading Auditory Lab has provided evidence that the distorting effects of reverberation are ameliorated by perceptual mechanisms which effect constancy.
Because the ratio of reflected to direct sound energy increases with distance between source and listener, the distortion of a sound’s temporal envelope increases with distance. Spectral distortion also varies, not only between different environments, but also between different pairs of source-listener positions within the same space. Any detectable difference between competing speech messages will help a listener to track one of them, so it seems reasonable to ask whether these position-specific distortions could serve to aid auditory selective attention when faced with the problem of multiple talkers in a reverberant space. However, the classic inter-aural cues arising from position differences which enable listeners to localise sounds are known to be highly vulnerable to reverberation. So does reverberation help or hinder auditory selective attention? Talker characteristics are the other main source of differences between speech messages, and cues arising from these differences are more robust in reverberation. The series of experiments I will describe in this talk therefore place talker differences in conflict with position differences, while listening in reverberation measured from real rooms, in order to study the effects of realistic reverberation on auditory selective attention.
Short Bio: Simon got his start in auditory psychology in Anthony Watkins’ lab at Reading, working on a project
investigating perceptual constancy for spectral envelope distortion. He got his masters in speech
and hearing sciences from UCL then completed a PhD in auditory modelling at Sheffield University,
supervised by Guy Brown, one of the pioneers of Computational Auditory Scene Analysis (CASA). His
PhD work involved using both perceptual experiments and computer modelling to study the role
of pitch in concurrent vowel segregation. After returning to Watkins’ lab at Reading a collaborative
project between Reading and Sheffield was born. This aims to use the results of perceptual
experiments investigating constancy in reverberation when temporal envelopes vary, to inform the
development of a computer model for use as a front-end in reverberation-robust artificial listening
devices. Most recently, he has also been studying the effects of reverberation on auditory selective
attention.
Project page: http://www.personal.reading.ac.uk/~sxs04sjm/constancy/
Personal page: http://www.reading.ac.uk/pcls/people/s-j-makin.aspx
Dates & times
| Date | Time | Add to calendar |
|---|---|---|
| 7 Dec 2011 | 4:00pm - 5:00pm |
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