The Effect of Nonlinear Distortion on the Perceived Quality of Music and Speech Signals
The Effect of Nonlinear Distortion on the Perceived Quality of Music and Speech Signals
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非线性失真对音乐和语音信号感知质量的影响
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
N. Zacharov
中科院分区：
文献类型：
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作者：
Chin;B. Moore;N. Zacharov
研究了各种非线性失真对语音和音乐信号感知质量的影响。在实验I和2中，使用人工失真，包括各种量的硬和软对称和不对称峰值削波、中心削波和通过将波形的瞬时绝对值提高到幂（<$=1）而产生的全范围波形失真，同时保持符号。受试者被要求对感知到的失真量进行评分，满分为10分（其中1分为最失真，10分为最不失真）。在实验1中，失真被施加到宽带信号。在实验2中，失真被施加到信号的子带。结果是高度一致的科目和测试会话。中心削波和软削波对收视率的影响很小，而硬削波和全范围失真的影响很大。主观评级进行了比较，以物理措施的失真的基础上多音测试信号。从每个非线性系统的输出频谱响应于10分量多音信号得到的失真测量，DS，给出了高的负相关性与主观评级（相关性是负的，因为DS的大值与低评级相关联）。进一步的实验是使用刺激进行的，通过记录真实的换能器的输出来引入非线性失真。对输出信号进行数字滤波，以尽可能减少幅频响应的不规则性。结果表明，适度强的主观评级和客观措施DS之间的负相关。得出的结论是，基于使用多音频信号的非线性失真的客观测量可以合理地预测非线性失真的感知效果。
The effect of various types of nonlinear distortion on the perceived quality of speech and music signals was examined. In experiments I and 2, artificial distortions were used, including hard and soft symmetrical and asymmetrical peak clipping of various amounts, center clipping, and full-range waveform distortion produced by raising the instantaneous absolute value of the waveform to a power (¬=1) while preserving the sign. Subjects were asked to rate the perceived amount of distortion on a ten-point scale (where 1 was most distorted and 10 least distorted). In experiment 1 the distortions were applied to the broadband signals. In experiment 2 the distortions were applied to subbands of the signal. Results were highly consistent across subjects and test sessions. Center clipping and soft clipping had only small effects on the ratings, whereas hard clipping and the full-range distortions had large effects. The subjective ratings were compared to physical measures of distortion based on multitone test signals. A distortion measure, DS, derived from the output spectrum of each nonlinear system in response to a 10-component multitone signal gave high negative correlations with the subjective ratings (correlations were negative as large values of DS were associated with low ratings). A further experiment was conducted using stimuli for which nonlinear distortion was introduced by recording the outputs of real transducers. The output signals were digitally filtered to reduce irregularities in the amplitude-frequency response as far as possible. The results showed moderately strong negative correlations between the subjective ratings and the objective measure DS. It was concluded, that an objective measure of nonlinear distortion based on the use of a multitone signal can predict the perceptual effects of nonlinear distortion reasonably well.