Pseudo-pitch tracking


Eric J. Fimbel - Research results and data sets - home page 

This page replaces http://www.ele.etsmtl.ca/profs/efimbel/soundInterface/

Citation: Fimbel, E.J. (2009) Pseudo-pitch tracking. Available at http://sites.google.com/site/pseudopitch/. Last retrieved : (mm/dd/yyyy)

Publication: Fimbel, E.J., Abiza, R.(2006) Tracking the pseudo-pitch of unvoiced sounds: a hand-free interface modality for disabled users. in procs. of IEEE ISIE'06 Conference, Montréal, July 2006, (1), 553-558. download draft (pdf) 



The sounds produced by inspiration and expiration are unvoiced, i.e., the vocal cords do not vibrate. Unvoiced sounds have no pitch, i.e, no fundamental frequency. Instead, they present a marked formant F1, i.e., a peak of energy typically around 1KHz.  Here are examples of voiced vs. unvoiced sounds:







Unvoiced sounds can convey information almost in the same way than voiced sounds. It is possible to produce unvoiced speech (whispering) as well as unvoiced tones. unvoiced tones, the first formant plays the role of the pitch, i.e., it determined the perceived height of the sound. We call this formant pseudo-pitch. Its frequency is controlled by the air flow and the configuration of the mouth cavity, the tongue and the lips.Here are two examples of controlled pseudo-pitch.


Breathing provides a coarse but efficient control of the pseudo-pitch: there is a marked difference between inspirations and expirations


Unvoiced sounds provide a nice hand-free modality for interfaces, whether for disabled users or advanced users that can use multimodal entries. The frequency spectrum of voice and unvoiced sounds are markedly different, therefore it may be possible to use speech and pseudo-pitch modulation with a single microphone.


Copyright: (c) 2005-2006 E.J. Fimbel, R.Abiza, ETS. This is open-access content distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This data contain no sociodemographic or personal information about participants.