Speech enhancement using vector quantization and a formant distance measure

A system to improve the intelligibility of noisy speech through the use of vector quantization of linear predictive coding (LPC) spectra and a distance measure involving formants is described. Based on experiments using the system on natural speech degraded by additive white noise, the approach appears to be a promising way to transform noisy speech into more intelligible signals. As the noise corruption increases (and SRN decreases), the output speech becomes more distorted in terms of spectral jumps and mismatches, but remains free of noise. Good intelligibility remains as low as 9 dB SNR, although the speech is unnatural due to the LPC synthesis