Beware of the ‘telephone effect’: the influence of telephone transmission on the measurement of formant frequencies
Beware of the ‘telephone effect’: the influence of telephone transmission on the measurement of formant frequencies
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当心“电话效应”：电话传输对共振峰频率测量的影响
DOI：
10.1558/ijsll.v8i1.80
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发表时间：
2001
影响因子：
0.4
通讯作者：
H. Künzel
中科院分区：
文献类型：
--
作者：
H. Künzel
语音科学家经常不得不处理通过电话传输的语音信号。虽然电话传输的声学特性，如带通滤波器特性是众所周知的，很少有人注意到它们对语音参数测量的影响。本研究探讨了元音共振峰的传输通道的较低截止斜率引入的伪影。出于理论原因，频率分量可以被假定为衰减得越低。因此，可以预期大多数元音的F1受影响最大。共振峰的较低分量的衰减将必然增加用于确定共振峰的较高分量的相对权重，并且因此导致其中心频率的人为向上偏移。对10名男性和10名女性受试者的直接和电话传输样本的实证调查表明，除了/a/之外，所有测试元音的F1预测效果实际上都发生了，其F1太高而不受带通斜率的影响。从这些文物所产生的测量误差的后果进行了讨论，特别提到说话人识别和经验方言。
Speech scientists often have to work with speech signals that have been transmitted over the telephone. Although the acoustic properties of telephone transmission such as the band-pass filter characteristics are well known, little attention has been paid to their effect on the measurement of speech parameters. This study deals with artefacts introduced by the lower cut-off slope of the transmission channel on vowel formants. For theoretical reasons, frequency components may be assumed to be attenuated the lower they are. Therefore F1 of most vowels can be expected to be affected most. Attenuation of the lower components of a formant will necessarily increase the relative weight of the higher components for the determination of a formant and thus cause an artificial upward shift of its centre frequency. An empirical investigation with directly and telephone-transmitted samples from ten male and ten female subjects shows that the predicted effect on F1 does in fact occur for all tested vowels except /a/, whose F1 is too high to be affected by the slope of the band-pass. The consequences of measurement errors arising from such artefacts are discussed with special reference to speaker identification and empirical dialectology.