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1. (WO1998048737) ACTIVE HEADSET WITH BRIDGE AMPLIFIER

Pub. No.:    WO/1998/048737    International Application No.:    PCT/US1998/007948
Publication Date: Fri Nov 06 00:59:59 CET 1998 International Filing Date: Tue Apr 21 01:59:59 CEST 1998
IPC: A61F 11/14
G10K 11/178
Applicants: NCT GROUP, INC.
Inventors: JONES, Owen
Title: ACTIVE HEADSET WITH BRIDGE AMPLIFIER
Abstract:
An active headset providing for reduction of external noise over a given frequency range by a microphone which generates an external noise cancellation signal spectrum, wherein a bridge amplifier circuit is interposed between the microphone (10) and the loudspeaker (20) and the gain of the bridge amplifier for peak amplitude of the noise cancellation signal is user adjustable (30) without substantially reducing the breadth of the given frequency range over which noise reduction is effective.