Emanuel F W, Whitehead R L
J Speech Hear Res. 1979 Dec;22(4):829-40. doi: 10.1044/jshr.2204.829.
In this study the effects of vowel roughness on the level of harmonics in test vowel spectra were investigated. Twenty normal-speaking adult males sustained productions of each of the vowels (formula: see text) first normally and then with simulated abnormal vocal roughness, at one intensity. A tape recording of each production was rated for roughness on an equal-appearing intervals scale by 11 judges and was also analyzed to obtain its 3-Hz bandwidth amplitude-by-frequency acoustic spectrum. The median roughness rating, the level of the first five spectral harmonics, and the f0 of each production were obtained. It was found that the level of the first three harmonics for each test vowel diminished with an increase in roughness (as was hypothesized from earlier results), but the higher harmonics of /u/ and /i/ showed some reversals. A moderately large negative correlative relationship was shown between lower-harmonic levels and median vowel roughness. A possible explanation of the higher-harmonic reversals was offered. The results suggest that spectral noise level measurements may provide a more reliable acoustic index of vowel wave aperiodicity and vowel roughness than measurements of harmonic level.
在本研究中，对测试元音频谱中谐波水平的元音粗糙度效应进行了研究。20名正常发声的成年男性，首先以一种强度正常发每个元音（公式：见正文），然后模拟异常的嗓音粗糙度来发每个元音。11名评判员按照等距量表对每次发音的录音进行粗糙度评分，并且对录音进行分析以获得其3赫兹带宽的逐频率声谱图。得到每次发音的粗糙度评分中位数、前五个频谱谐波的水平以及基频。结果发现，每个测试元音的前三个谐波水平随着粗糙度的增加而降低（正如根据早期结果所假设的那样），但是/u/和/i/的较高谐波表现出一些反转。较低谐波水平与元音粗糙度评分中位数之间呈现出适度的强负相关关系。对较高谐波反转现象给出了一种可能的解释。结果表明，与谐波水平测量相比，频谱噪声水平测量可能为元音波形非周期性和元音粗糙度提供更可靠的声学指标。
