Perceptual musical noise reduction using critical bands tonality coefficients and masking thresholds

Speech enhancement techniques using spectral subtraction have the drawback of generating an annoying musical noise. We develop a new post-processing method for reducing it in each critical-band. In the proposed technique, the difference between tonality coefficients of the noisy speech and the denoised one constitutes one step for detection. Next, using a modified Johnston masking threshold, we detect the so-called “critical-band musical noise”. The reduction is simply done by undertaking the power spectral density of detected musical noise under the masking thresholds. Simulation results using different criteria are presented to validate proposed ideas and to show that enhanced speech is characterized by low distortion and inaudible musical noise.