EP 0040462 A1 19811125 - Electroacoustical audible noise reducing apparatus.
Title (en)
Electroacoustical audible noise reducing apparatus.
Title (de)
Vorrichtung zur elektro-akustischen Dämpfung von Schallschwingungen im hörbaren Bereich.
Title (fr)
Appareil électro-acoustique pour réduire le bruit audible.
Publication
Application
Priority
US 15058180 A 19800516
Abstract (en)
The noise power perceived in an environment of volume larger than and outside a volume including a source (11) of audible noise is appreciably reduced with an active system that includes an acoustical combiner (13) that combines the noise signal to be reduced with an inversely fed back signal provided by a loudspeaker (14) energized by a controlled frequency selective amplifier (16) that amplifies spectral components to be reduced provided by a microphone (15) near the output of the acoustical combiner (13).
IPC 1-7
IPC 8 full level
G10K 11/178 (2006.01)
CPC (source: EP US)
G10K 11/17857 (2017.12 - EP US); G10K 11/17875 (2017.12 - EP US); G10K 2210/112 (2013.01 - EP); G10K 2210/12822 (2013.01 - EP); G10K 2210/3011 (2013.01 - EP); G10K 2210/3013 (2013.01 - EP); G10K 2210/3217 (2013.01 - EP)
Citation (search report)
- GB 1357330 A 19740619 - SECR DEFENCE
- US 3936606 A 19760203 - WANKE RONALD L
- US 2043416 A 19360609 - PAUL LUEG
- US 3826870 A 19740730 - WURM R, et al
- FR 2275722 A1 19760116 - SOUND ATTENUATORS LTD [GB]
Designated contracting state (EPC)
BE DE FR GB IT LU NL
DOCDB simple family (publication)
DOCDB simple family (application)
EP 81300660 A 19810218; JP 4998981 A 19810402