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By numerical simulations on frequency dependence of the spiking threshold, i.e. on the critical amplitude of periodic stimulus, for a neuron to fire, we find that bushy cells in the cochlear nuclear exhibit frequency selec- tivity behaviour. However, the selective frequency band of a bushy cell is far away from that of the preferred spectral range in human and mammal auditory perception. The mechanism underlying this neural activity is also discussed. Further studies show that the ion channel densities have little impact on the selective frequency band of bushy cells. These findings suggest that the neuronal behaviour of frequency selectivity in bushy cells at both the single cell and population levels may be not functionally relevant to frequency discrimination. Our results may reveal a neural hint to the reconsideration on the busily cell functional role in auditory information processing of sound frequency. 相似文献
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ZHANG Jialu 《声学学报:英文版》2006,25(3):204-208
It has been a barrier that the place code is far too coarse a mechanism to account for the finest frequency difference limen for place theory of hearing since it was proposed in 19th century. A place correlation model, which takes the energy distribution of a pure tone in neighboring bands of auditory filters into full account, was presented in this paper. The model based on the place theory and some experimental results of the psychophysical tuning curves of hearing can explain the finest difference limen for frequency (about 0.02 or 0.3% at 1000 Hz) easily. Using a standard 1/3 octave filter bank of which the relationship between the frequency of a input pure tone apart from the centre frequency of K-th filter band, Δf, and the output intensity difference between K-th and (K l)-th filters,ΔE, was established in order to show the fine frequency detection ability of the filter bank. This model can also be used to abstract the fundamental frequency of speech and to measure the frequency of pure tone precisely. 相似文献
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变上限积分是积分学的一个重要理论,其运算结果仍以函数的形式体现.研究这类函数,得出几个颇有理论意义的定理。 相似文献
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LI Rongyan MA Yuanliang YANG Kunde 《声学学报:英文版》2007,26(4):345-357
This paper proposed a method for blind estimation of underwater channels in shallow water environment by using received data at a single hydrophone or from single beam. First,the received signal is used for source signal reconstruction by means of signal-dependent TF(Time-Frequency)distribution,in association with instantaneous frequency estimation and TF inversion.Then the shallow-water channel estimation is achieved via WRELAX technique by use of the received signal and the estimated source signal.Finally,the results of numerical simulation and experimental test from real data taken in South China Sea trial have proved satisfactory.It is shown that the proposed method is useful for underwater channel estimation. 相似文献
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三、心理声学 当前心理声学研究的主要趋向是从以往纯音听觉的单因素研究转向具有频谱时间表征的复合声的多维研究。这个转变和生理声学的发展情况恰成有趣的对比。如上节所述,生理声学的近期进展是对Helmholtz为代表的传统耳蜗观念的突破。与此相反,心理声学的前进却不能不回到Helmholtz在其名著“乐音感觉:音乐理论的生理学基础”一书中提出的一个基本课题,即对音乐、言语这类复合声的知觉。自然,这并不是说心理声学应该迳直去研究音乐和言语,去取代音乐声学和言语声学。在 相似文献
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