Patent ID: 8401845
Filing Date: 2013-03-19
Classification: G10L

Abstract:
1. A system for enhancing a tonal sound signal decoded by a decoder of a speech-specific codec in response to a received coded bit stream, comprising: a spectral analyser responsive to the decoded tonal sound signal to produce spectral parameters representative of the decoded tonal sound signal, wherein the spectral parameters comprise a spectral energy of the decoded tonal sound signal calculated by the spectral analyser; a classifier of the decoded tonal sound signal into a plurality of different sound signal categories, wherein the signal classifier comprises a finder of a deviation of a variation of the calculated signal spectral energy over a number of previous frames of the decoded tonal sound signal; and a reducer of a quantization noise in low-energy spectral regions of the decoded tonal sound signal in response to the spectral parameters from the spectral analyzer and the classification of the decoded tonal sound signal into the plurality of different sound signal categories.