Abstract
As one of the method to extract pitches from commercial telephone line, the improvement in Halsey's pitch extractor shows preferable results. This paper reveales some experimental results under the condition of no artificial exchange for both male and female voice in using #4 telephone sets. The principle is same as the Halsey's one, but the main feature of our method is to use electrical filters more than three for the purpose. Four low pass filters are used in our laboratory, and the total pitch extraction band width is 80 to 380 cps.
