A robust 400-bps speech coder against background noise

Author

Liu, Y.J.

Author_Institution

ITT Aerosp., Commun. Div., Nutley, NJ, USA

fYear

1991

fDate

14-17 Apr 1991

Firstpage

601

Abstract

The 400-bps speech was unintelligible in helicopter noise. A detailed study has shown that both voicing errors and spectral distortion are the key to the loss of intelligibility. The voicing accuracy is restored by first generating robust features whose distributions are not strongly dependent upon noise levels. These features are then appropriately combined using linear programming. A better spectrum is generated by using the approach of adaptive vector quantization. This means the codebook is updated based upon noise level and subsequently searched to determine the best clean codeword for synthesis. Both approaches show promise for improved speech intelligibility in noise for a low-rate coder

Keywords

acoustic noise; speech intelligibility; vocoders; 400 bit/s; LPC; adaptive vector quantization; background noise; helicopter noise; linear programming; low-rate coder; noise levels; robust features; spectral distortion; speech coder; speech intelligibility; voicing accuracy; voicing errors; Background noise; Decoding; Helicopters; Linear predictive coding; Low pass filters; Low-frequency noise; Noise level; Noise robustness; Speech enhancement; Vector quantization;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 1991. ICASSP-91., 1991 International Conference on

Conference_Location

Toronto, Ont.

ISSN

1520-6149

Print_ISBN

0-7803-0003-3

Type

conf

DOI

10.1109/ICASSP.1991.150411

Filename

150411