Granted Patent
Utility
US 5,164,989 · App. 07/625,368
Echo cancellation methods and apparatus for voice processing systems
Inventors:
Yigal Brandman, Manoj Puri
Patented Case
View Patent ↗
Granted: Nov 17, 1992
Filed: Dec 11, 1990
Inventors
Yigal Brandman
Manoj Puri
Assignee (at issue)
Octel Communications Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.