Accession Number : ADA311062

Title :   Smoothing Disjoint Formant Track Boundaries Caused by Waveform Substitution in Packet Voice Communication.

Descriptive Note : Professional paper,

Corporate Author : NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA

Personal Author(s) : VonColln, E. ; Gonchaaroff, V.

PDF Url : ADA311062

Report Date : MAY 1996

Pagination or Media Count : 7

Abstract : This paper describes a method for smoothing disjoint formant track boundaries that can arise in packet voice communication. The disjoint boundaries can occur when missing packets are reconstructed using waveform substitution methods. Our algorithm attempts to match formant locations to LPC-poles and then adjusts the pole locations across the boundary to smooth the formants at the boundary. We describe our method for matching formants to poles and our method for adjusting the poles. The LPC residual is not modified. Time domain plots and LPC spectrograms are used to show that the formant track was smoothed. Perceptually subjective listening tests confirm that an improvement in the speech quality is achieved with this method in that it sounds more clear and natural.

Descriptors :   *WAVEFORMS, *BOUNDARIES, *CODING, *SUBSTITUTES, *VOICE COMMUNICATIONS, TEST AND EVALUATION, ALGORITHMS, PACKETS, QUALITY, SPEECH, TIME DOMAIN, PLOTTING, HEARING, SPECTROGRAPHY, PHONEMES.

Subject Categories : Voice Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE