Granted Patent
Utility
US 6,539,096 · App. 09/280,632
Method for producing a variable directional microphone characteristic and digital hearing aid operating according to the method
Inventors:
Ullrich Sigwanz, Fred Zoels
Patented Case
View Patent ↗
Granted: Mar 25, 2003
Filed: Mar 29, 1999
Inventors
Ullrich Sigwanz
Fred Zoels
Assignee (at issue)
Siemens Audiologische Technik GmbH
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.