Method and apparatus for adaptive volume control for a radiotele
Method and apparatus for reducing false ringback detection
Multi-function telephone apparatus and control method
Noise cancellation apparatus
Noise cancelling apparatus for a telephone handset
Noise-canceling differential microphone assembly
Nonsaturating interface supply
Option bus
Option bus adapter
Outbound noise cancellation for telephonic handset
Portable telecommunications test instrument with a talk battery
Portable telephone apparatus
Post assembly process for adjusting the gain of an electret micr
Power source control apparatus for telephone set
Private branch exchange system
Programmable telephone
Programmable telephone amplifier circuit interface
Protocol adaptation
Self-configuring telephone interface unit
Smart interface technology