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Pitch Detection

IP.com Disclosure Number: IPCOM000083566D
Original Publication Date: 1975-Jun-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Galand, C: AUTHOR

Abstract

In voice signal processing systems, the pitch detection is a very important feature. Errors in measuring the pitch value, for instance in a voice analyzer, located at the transmitting end of a communication channel, would lead to a wrong and probably unintelligible voice recovered at the receiving end.

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Pitch Detection

In voice signal processing systems, the pitch detection is a very important feature. Errors in measuring the pitch value, for instance in a voice analyzer, located at the transmitting end of a communication channel, would lead to a wrong and probably unintelligible voice recovered at the receiving end.

Pitch detection is generally obtained by processing the voice signal. by this vocal tract transfer of glottal signal, a low-pass filter is used. The filtered output is then processed for providing a signal with peaks located at a pitch period by any conventional method (see for instance, Frei et al article entitled "Adaptive Predictive Coding Based on Pitch-Controlled Interruption - Reiteration Techniques" in International Conference on Communications, Seattle, Washington, June 1973). When defining the transfer characteristics of the filter great care must be taken not to emphasize any harmonic with respect to the pitch itself, whatever be the locutor and his pitch. This filter is thus defined with a linear characteristic, say 12 db/octave between 80 and 500 Hz. Since any human pitch is located between these values, the first harmonic of any locutor's pitch is attenuated by at least 12 db. This increases the pitch detection efficiency by roughly 20%.

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