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:
Mar. 29, 1977
Filed:
Oct. 31, 1975
John Joseph Dubnowski, Hampton, NJ (US);
Lawrence Richard Rabiner, Berkeley Heights, NJ (US);
Ronald William Schafer, Atlanta, GA (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Apparatus for the real-time analysis of speech signals in which a digital signal representative of the speech signal is adaptive threshold center-clipped and infinite peak-clipped to form a signal comprising three logic states (+1,0,-1). The autocorrelation function of this signal is determined by a circuit which employs simple combinational logic and an updown counter circuit. Pitch period and voiced-unvoiced indication are determined from the location and magnitude of the peak value of the autocorrelation function. Additionally, a signal representative of the speech energy is provided by summing the digital speech signals over a predetermined time interval and intervals of silence are detected by comparing the speech energy in an interval of time with a predetermined or adaptively determined threshold energy.