EP 0327617 B1 19921104 - IMPROVEMENTS RELATING TO NOISE REDUCTION SYSTEMS
Title (en)
IMPROVEMENTS RELATING TO NOISE REDUCTION SYSTEMS
Publication
Application
Priority
- GB 8717040 A 19870720
- GB 8717042 A 19870720
- GB 8717043 A 19870720
Abstract (en)
[origin: WO8900746A1] Active noise reduction systems. In order to overcome problems in an active noise reduction system of sound buffets at low frequency and signal enhancement caused by imperfect transfer functions of a noise cancelling sound generator and a microphone, one or more high pass filters for reducing low frequency signals are provided in a feedback loop between the sound generator and microphone. A low pass filter is provided for extending the bandwidth of the system but which does not introduce unduly large phase shifts.
IPC 1-7
IPC 8 full level
G10K 11/16 (2006.01); G10K 11/178 (2006.01); H04R 3/00 (2006.01)
CPC (source: EP US)
G10K 11/17825 (2017.12 - EP US); G10K 11/17853 (2017.12 - EP US); G10K 11/17875 (2017.12 - EP US); G10K 11/17885 (2017.12 - EP US); G10K 2210/1081 (2013.01 - EP); G10K 2210/3028 (2013.01 - EP); G10K 2210/3039 (2013.01 - EP); G10K 2210/3045 (2013.01 - EP)
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI LU NL SE
DOCDB simple family (publication)
WO 8900746 A1 19890126; AT E82083 T1 19921115; AU 2071688 A 19890213; AU 608041 B2 19910321; CA 1299725 C 19920428; DE 3875717 D1 19921210; DE 3875717 T2 19930318; EP 0327617 A1 19890816; EP 0327617 B1 19921104
DOCDB simple family (application)
GB 8800581 W 19880720; AT 88905991 T 19880720; AU 2071688 A 19880720; CA 572420 A 19880719; DE 3875717 T 19880720; EP 88905991 A 19880720