Objective measures for quality assessment of noise-suppressed speech

• Three objective measures are proposed to separately evaluate the speech distortion, noise reduction and overall quality of the processed speech signal enhanced by single channel speech enhancement algorithms.
• The proposed measures are derived in both time and frequency domains.
• The high correlations between the measurement results of the proposed approaches and subjective ratings demonstrate the effectiveness of the proposed evaluation methodology.
• Some hints and links between signal parameters and perceptual judgements are revealed in our analysis on the evaluation process of the proposed objective measures with subjective ratings.

Among all the existing objective measures, few are able to provide a clearly specific indication of speech distortion or noise reduction, which are the two key metrics to assess the performance of speech enhancement algorithms and evaluate the noise-suppressed speech quality. In this paper, new quantitative quality assessments are proposed to separately evaluate the capabilities of single channel speech enhancement algorithms in terms of maintaining the clean speech, noise reduction and overall performance. Based on these aspects, three evaluation results can be provided for any one test speech signal by analyzing the residual signal which is the difference between the clean speech and the processed speech. Several common speech enhancement algorithms are compared by these objective measures as well as subjective listening tests. High correlations between the scores of the objective measures and subjective ratings clearly show the effectiveness of the proposed evaluation methodologies on the different speech enhancement algorithms.