Speech enhancement using a constrained iterative sinusoidal model

This paper presents a sinusoidal model based algorithm for enhancement of speech degraded by additive broad-band noise. In order to ensure speech-like characteristics observed in clean speech, smoothness constraints are imposed on the model parameters using a spectral envelope surface (SES) smoothing procedure. Algorithm evaluation is performed using speech signals degraded by additive white Gaussian noise. Distortion as measured by objective speech quality scores showed a 34%-41% reduction over a SNR range of 5-to-20 dB. Objective and subjective evaluations also show considerable improvement over traditional spectral subtraction and Wiener filtering based schemes. Finally, in a subjective AB preference test, where enhanced signals were coded with the G729 codec, the proposed scheme was preferred over the traditional enhancement schemes tested for SNR's in the range of 5 to 20 dB.