The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 2000
Filed:
Aug. 04, 1997
Hideki Kawahara, Kyoto, JP;
Abstract
A speech signal input from a microphone is distributed by a distribution amplifier. Using output signals of a filter group of cos phase having cut-off frequency moderate on low frequency side and steep on high frequency side and of similar filter group of sin phase, stability index is calculated based on magnitude of amplitude modulation and magnitude of frequency modulation of the signals, by stability index calculating portion and fundamental frequency extracting portion. Based on the result of calculation, approximate value of fundamental frequency is calculated based on an output of a channel indicating maximum stability, and based on the approximate value of fundamental frequency, instantaneous frequency extracting portion extracts precise instantaneous frequency as fundamental frequency, interpolating value of instantaneous frequency from adjacent frequency channels.