(19)

(11)

EP 0 647 372 A1

(12)

(43) Date of publication: 12.04.1995 Bulletin 1995/15 (21) Application number: 92914435.0 (22) Date of filing: 25.06.1992

(51) International Patent Classification (IPC):  G10K 11/ 178( . ) H04B 1/ 10( . ) H03B 1/ 04( . ) (86) International application number: PCT/US1992/005228 (87) International publication number: WO 1994/000911 (06.01.1994 Gazette 1994/02)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU MC NL SE (71) Applicant: NOISE CANCELLATION TECHNOLOGIES, INC. Linthicum, MD 21090 (US)	(72) Inventor: EATWELL, Graham Linthicum, MD 21090 (US) (74) Representative: Wilhelm & Dauster Patentanwälte European Patent Attorneys  Hospitalstrasse 8 D-70174 Stuttgart D-70174 Stuttgart (DE)