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:
May. 15, 2001
Filed:
Mar. 12, 1999
Applicant:
Inventors:
Azhar Mustapha, Germantown, MD (US);
Suat Yeldener, Germantown, MD (US);
Assignee:
Comsat Corporation, Bethesda, MD (US);
Primary Examiner:
Int. Cl.
CPC ...
G10L 1/904 ;
U.S. Cl.
CPC ...
G10L 1/904 ;
Abstract
An adaptive time-domain post-filtering technique is based on the modified Yule-Walker filter. This technique eliminates the problem of spectral tilt in speech spectrum that can be applied to various speech coders. The new post-filter has a flat frequency response at the formant peaks of speech spectrum. Information is gathered about the relation between poles and formants and then the formants and their bandwidths are estimated. The information about the formants and their bandwidths is then used to design the modified Yule-Walker filter based on a least squares fit in time domain.