Multi-referenced correction of the voice timbre distortions on telephone network
Résumé
In a telephone link, the voice timbre is impaired by spectral distortions generated by the analog parts of the link. We first evaluate from a perceptual point of view an equalization method consisting in matching the long term spectrum of the processed signal to a reference spectrum. This evaluation shows a satisfying restoration of the timbre for most speakers. For some speakers however, a noticeable spectral distortion remains. That is why we propose a multi-referenced equalizer, based on a classification of speakers and using a different reference spectrum for each class. This leads to a decrease of the spectral distortion and, as a consequence, to a significant improvement of the timbre correction.