Aulanko R, Hari R, Lounasmaa O V, Näätänen R, Sams M
Department of Phonetics, University of Helsinki, Finland.
Neuroreport. 1993 Sep 30;4(12):1356-8. doi: 10.1097/00001756-199309150-00018.
Neuromagnetic signals evoked by synthesized syllables (/bae/ and /gae/) were recorded over the left auditory cortex of healthy humans. The fundamental frequencies of the syllables varied as if the same speaker had pronounced them at 16 different pitches. Specific mismatch responses to infrequent syllables among frequent syllables of the other type indicated that phonetically invariant information had been extracted at the level of the auditory cortex from the extensive irrelevant pitch variation. Such a detection mechanism is necessary for perceiving speech sounds in natural situations with a great deal of acoustic variation present.
在健康人类的左侧听觉皮层记录了由合成音节（/bae/和/gae/）诱发的神经磁信号。这些音节的基频有所变化，就好像是同一个说话者以16种不同音高发出这些音节一样。对另一种类型的频繁音节中不常见音节的特定失配反应表明，从大量无关的音高变化中，在听觉皮层水平已经提取了语音不变信息。在存在大量声学变化的自然情境中感知语音时，这样一种检测机制是必要的。
