Deal R E, Emanuel F W
J Speech Hear Res. 1978 Jun;21(2):250-64. doi: 10.1044/jshr.2102.250.
Acoustic wave-period variation (jitter) and acoustic wave-amplitude variation (shimmer) associated with vowel phonations representing a range of vocal roughness were investigated. Twenty normal-speaking adult males phonated each of the vowels /u/, /i/, /v/, /a/, and /ae/, first normally and then with simulated abnormal vocal roughness. Twenty hoarse adult males, each presenting a medically diagnosed laryngeal pathology, also produced each of the five test vowels. To provide a measurable presentation of the frequency and amplitude variations of interest, each recorded vowel was band-pass filtered to isolate the fundamental frequency component. Relations of the jitter and shimmer indices (obtained from the filtered vowel waves) to acoustic spectral noise levels and to roughness ratings for the vowel phonations were studied. The findings supported the hypothesis that increases in vowel acoustic wave variability (estimated by period or amplitude variation or both) are associated with increases in vowel spectral noise levels and perceived vowel roughness. The findings also suggested, for most of the vowels studied, that cyclic peak amplitude variation may provide a better index of perceived roughness than cyclic period variation. Vowel spectral noise levels, however, may provide a more clinically useful indicant of vowel roughness than the waveform variability indices derived from the filtering procedure employed in this study.
研究了与一系列嗓音粗糙度的元音发声相关的声波周期变化（抖动）和声波幅度变化（闪烁）。20名正常发声的成年男性分别发/u/、/i/、/v/、/a/和/ae/这几个元音，先是正常发声，然后模拟异常嗓音粗糙度发声。20名嗓音嘶哑的成年男性，每人都患有经医学诊断的喉部疾病，也分别发出这五个测试元音。为了对感兴趣的频率和幅度变化进行可测量的呈现，对每个录制的元音进行带通滤波以分离基频成分。研究了抖动和闪烁指数（从滤波后的元音波中获得）与元音发声的声谱噪声水平和粗糙度评级之间的关系。研究结果支持了这样的假设，即元音声波变异性的增加（通过周期或幅度变化或两者来估计）与元音声谱噪声水平的增加以及感知到的元音粗糙度增加有关。研究结果还表明，对于大多数所研究的元音来说，循环峰值幅度变化可能比循环周期变化提供更好的感知粗糙度指标。然而，元音声谱噪声水平可能比本研究中采用的滤波程序得出的波形变异性指标更具临床实用性，可作为元音粗糙度的指标。
