摘要
当一高频纯音被另一低频正弦波调幅时,从复合声中可听到清楚并占主导的调制波音调。后者随调幅波的频率而变,其辨别阈(△f_(am))可在动物用记录皮层慢反应的方法测定。本工作系统地研究了豚鼠△f_(am)与载波频率、调制波频率、调幅深度、调幅时程、声音强度等的关系。豚鼠对调制波频率似有较好的辨别能力,刺激参数合适时△f_(am)只3—4Hz,与该种动物对纯音的频率辨别阈相近。文中对比了人和豚鼠的△f_(am),并讨论了调制波音调的感受和辩别机理。
If a high frequency tone is amplitude-modulated by another sine wave of low frequency a distinct and predominating modulator pitch can be heard which changes when the mo-昫ulator frequency is in turn modulated by a rectangular pulse. Thresholds of frequency discrimination of such amplitude-modulator (Δfam) can be measured in guinea pigs by recording the slow cortical responses evoked by its frequency-modulation. Δfam in relation to the carrier and, modulator frequencies, to the depth and duration of amplitude modulation, and to sound intensity are systematically studied. In guinea pigs the ability of modulator pitch discrimination seems rather good. At optimal stimulus parameters the guinea pig Δfam amounts to 3-4 Hz, quite close to its frequency differential thresholds of pure tones. A/em in guinea pigs and in humans (measured by psychophysical method) are compared and mechanism of modulator pitch perception and discrimination discussed.
出处
《声学学报》
EI
CSCD
北大核心
1989年第4期282-287,共6页
Acta Acustica
基金
中国科学院科学基金资助课题
