Adaptive speech filter
CA 2209409 C · Owner: Davis, Kenneth P. · Inventors: Davis, Kenneth P.; Eatwell, Graham P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to an improved adaptive spectral estimator for estimating the spectral components in a signal containing both an information signal, such as speech and noise. The improvements relate to a noise power estimator (3) and a computationally efficient gain calculation method. The adaptive spectral estimator is particularly suited to implementation using digital signal processing and can be used to provide improved spectral estimates of the information signal. It can be combined with a speech or voice recognition system. A further object of the invention is to provide an accurate method for voice detection.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed January 29, 1996 and granted December 18, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 29, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 29, 2018.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.