Granted Patent
Utility
US 6,226,303 · App. 09/036,342
DTMF tone detection and suppression with application to computer telephony over packet switched networks
Inventors:
Bruce C. Levens, Paul Kerr, William Scott Hoge, Daniel F. Daly
Patented Case
View Patent ↗
Granted: May 1, 2001
Filed: Mar 6, 1998
Inventors
Bruce C. Levens
Paul Kerr
William Scott Hoge
Daniel F. Daly
Assignee (at issue)
Natural MicroSystems 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.