Masao Kasuga

Method of determining a sound localization filter and a sound localization control system incorporating the filter

A method of determining a sound localization filter for approximation of a head related transfer function. The method comprises storing a plurality of sets of initial parameters with respect to a plurality of predetermined direction angles about a front position of a listener into a memory, reading one of the sets of initial parameters from the memory in accordance with a localization shift signal, calculating an optimum filter parameter based on the read initial parameters, the optimum filter parameter needed to approximate desired frequency characteristics of the head related transfer function, determining filter coefficients of the sound localization filter based on the optimum filter parameter and supplying the determined filter coefficients to a coefficient buffer provided for the sound localization filter.

Voiceband modem control algorithm for improving image quality of mobile telephone facsimile

The authors describe the control algorithm of V.27ter voiceband modem function for improving the image quality of mobile telephone facsimiles and present the results of field experiments to verify the effectiveness of that algorithm. First, impairments unique to the mobile telephone network, in which an analog cellular system is connected with the public switched telephone network (PSTN), are described. Second the impairment of incoming signals mobile telephone facsimile is shown and the key aspects of the voiceband modem control algorithm are described. Finally, the authors show, through experimental results, that the developed modem DSP chip can improve the image quality of mobile telephone facsimile.<<ETX>>