On the place theory and the frequency difference limen of hearing

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 which was proposed in 19^th century. A place correlation model, which takes the energy distribution of a pure tone in neighboring bands of hearing filters into full account, was put forward in this paper. The model based on the place theory and some experimental results on the psychophysical tuning curves of hearing can explain the finest difference limen for frequency (about 0.3% at 1000 Hz) easily. Using a standard 1/3 octave filter bank the relationship between the frequency of a input pure tone apart from a center frequency of Kth filter band, △f, and the output intensity difference of Kth and (K + 1)th filters, △E, was established in order to show the fine frequency detection capability 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.