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1. (WO1998048737) ACTIVE HEADSET WITH BRIDGE AMPLIFIER
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1998/048737 International Application No.: PCT/US1998/007948
Publication Date: 05.11.1998 International Filing Date: 20.04.1998
Chapter 2 Demand Filed: 23.11.1998
IPC:
A61F 11/14 (2006.01) ,G10K 11/178 (2006.01)
A HUMAN NECESSITIES
61
MEDICAL OR VETERINARY SCIENCE; HYGIENE
F
FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
11
Methods or devices for treatment of the ears, e.g. surgical; Protective devices for the ears, carried on the body or in the hand
06
Protective devices for the ears
14
external, e.g. earcaps or earmuffs
G PHYSICS
10
MUSICAL INSTRUMENTS; ACOUSTICS
K
SOUND-PRODUCING DEVICES;  METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
11
Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
16
Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
175
using interference effects; Masking sound
178
by electro-acoustically regenerating the original acoustic waves in anti-phase
Applicants:
NCT GROUP, INC. [US/US]; 1025 West Nursery Road Linthicum, MD 21090, US
Inventors:
JONES, Owen; GB
Priority Data:
08/846,44330.04.1997US
Title (EN) ACTIVE HEADSET WITH BRIDGE AMPLIFIER
(FR) CASQUE D'ECOUTE ACTIF A AMPLIFICATEUR EN PONT
Abstract:
(EN) 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.
(FR) Casque d'écoute actif permettant la réduction du bruit extérieur sur une plage de fréquences donnée, au moyen d'un microphone qui génère un spectre de signaux d'annulation de bruit extérieur, un circuit amplificateur en pont étant placé entre le microphone (10) et le haut-parleur (20) et le gain de l'amplificateur en pont pour l'amplitude de crête du signal d'annulation de bruit étant ajustable (30) par l'utilisateur sans que la largeur de la plage de fréquences donnée dans laquelle la réduction de bruit est efficace ne soit sensiblement réduite.
Designated States: AU, CA, CN, ID, JP, KR
European Patent Office (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
EP1014894CA2289033AU1998071398MYPI 98001867