Spectral moments of the long-term average spectrum: Sensitive indices of voice change after therapy?
Spectral moments of the long-term average spectrum: Sensitive indices of voice change after therapy?
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DOI：
10.1016/j.jvoice.2004.02.005
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发表时间：
2005-06-01
期刊：
影响因子：
2.2
通讯作者：
Buder, EH
中科院分区：
文献类型：
--
作者：
Tanner, K;Roy, N;Buder, EH
嗓音临床医生需要一种客观、可靠和相对自动化的方法来评估内科、外科或行为干预后的嗓音变化。这一措施必须对各种声音质量和严重程度敏感，最好是反映连续语音中的声音。长期平均谱(LTAS)是一种快速傅里叶变换生成的功率谱，其特性可以通过谱矩分析与高斯钟形曲线进行比较。四个谱矩描述了LTA的特征：谱均值(矩1)和标准差(矩2)分别代表光谱的中心趋势和色散。偏度(基于矩3)和峰度(基于矩4)分别表示光谱的倾斜和峰值。为探讨发音功能障碍患者发声功能的前4个谱矩是否对发声改善敏感，本研究采用谱矩分析方法对93例功能性发音障碍患者治疗前后的嗓音样本进行了比较。对结果的检验表明，在成功的行为管理后，频谱平均值和标准差随着感知的声音改善而显著降低(p<；0.001)。然而，偏度和峰度的变化并不显著。此外，频谱均值的降低唯一地解释了治疗前到治疗后观察到的嗓音严重程度感知等级变化的方差的约14%(p<；0.001)，表明LTA的频谱均值(即，矩1)可能是对发音困难严重程度的改善敏感的一个声学标记。
Voice clinicians require an objective, reliable, and relatively automatic method to assess voice change after medical, surgical, or behavioral intervention. This measure must be sensitive to a variety of voice qualities and severities, and preferably should reflect voice in continuous speech. The long-term average spectrum (LTAS) is a fast Fourier transform-generated power spectrum whose properties can be compared with a Gaussian bell curve using spectral moments analysis. Four spectral moments describe features of the LTAS: Spectral mean (Moment 1) and standard deviation (Moment 2) represent the spectrum's central tendency and dispersion, respectively. Skewness (based on Moment 3) and kurtosis (based on Moment 4) represent the spectrum's tilt and peakedness, respectively. To examine whether the first four spectral moments of the LTAS were sensitive to perceived voice improvement after voice therapy, this investigation compared pretreatment and posttreatment voice samples of 93 patients with functional dysphonia using spectral moments analysis. Inspection of the results revealed that spectral mean and standard deviation lowered significantly with perceived voice improvement after successful behavioral management (p < 0.001). However, changes in skewness and kurtosis were not significant. Furthermore, lowering of the spectral mean uniquely accounted for approximately 14% of the variance in the pretreatment to posttreatment changes observed in perceptual ratings of voice severity (p < 0.001), indicating that spectral mean (ie, Moment 1) of the LTAS may be one acoustic marker sensitive to improvement in dysphonia severity.