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Class Information
Number: 181/206
Name: Acoustics > Sound-modifying means > By wave interference
Description: Subject matter wherein the means for modifying the sound includes modulating the sound by interacting or introducing an additional higher or lower frequency to the sound source, the resulting sound being at a different frequency.
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 7416051 |
Assembly and method for fan noise reduction from turbofan engines using dynamically adaptive Herschel-Quincke tubes |
Aug. 26, 2008 |
| 7380635 |
Interference-based exhaust noise attenuation |
Jun. 3, 2008 |
| 7353908 |
Method and system for attenuating noise from a cabinet housing computer equipment |
Apr. 8, 2008 |
| 7352870 |
Active sound muffler and active sound muffling method |
Apr. 1, 2008 |
| 7293627 |
Active exhaust muffler |
Nov. 13, 2007 |
| 7227957 |
Noise-suppressing receiver |
Jun. 5, 2007 |
| 7077164 |
Pipe |
Jul. 18, 2006 |
| 6896219 |
Process and apparatus for noise reduction in multi-engine propeller-driven aircraft |
May. 24, 2005 |
| 6796859 |
Air intake silencer |
Sep. 28, 2004 |
| 6786037 |
Segmented mixing device having chevrons for exhaust noise reduction in jet engines |
Sep. 7, 2004 |
| 6758304 |
Tuned Helmholtz resonator using cavity forcing |
Jul. 6, 2004 |
| 6702061 |
Environmentally protected microphone for an active noise control system |
Mar. 9, 2004 |
| 6688422 |
Method and apparatus for actively influencing the intake noise of an internal combustion engine |
Feb. 10, 2004 |
| 6684977 |
Speaker retention assembly for an active noise control system |
Feb. 3, 2004 |
| 6658118 |
Suppression of fluid-borne noise |
Dec. 2, 2003 |
| 6633646 |
Method and apparatus for controlling exhaust noise |
Oct. 14, 2003 |
| 6612106 |
Segmented mixing device having chevrons for exhaust noise reduction in jet engines |
Sep. 2, 2003 |
| 6557665 |
Active dipole inlet using drone cone speaker driver |
May. 6, 2003 |
| 6532729 |
Shelf truncated chevron exhaust nozzle for reduction of exhaust noise and infrared (IR) signature |
Mar. 18, 2003 |
| 6394062 |
Dust sensing assembly air intake system |
May. 28, 2002 |
| 6173806 |
Muffling wall |
Jan. 16, 2001 |
| 6072880 |
Modular active silencer with port dish |
Jun. 6, 2000 |
| 6005957 |
Loudspeaker pressure plate |
Dec. 21, 1999 |
| 5967863 |
Trolling motor |
Oct. 19, 1999 |
| 5959210 |
Vibration detecting apparatus and noise absorbent member |
Sep. 28, 1999 |
| 5919029 |
Noise absorption system having active acoustic liner |
Jul. 6, 1999 |
| 5884650 |
Suppressing cavitation in a hydraulic component |
Mar. 23, 1999 |
| 5860400 |
Intake-exhaust manifold bridge noise attenuation system and method |
Jan. 19, 1999 |
| 5828759 |
System and method for reducing engine noise |
Oct. 27, 1998 |
| 5703337 |
System for cancelling sound waves |
Dec. 30, 1997 |
| 5702230 |
Actively controlled acoustic treatment panel |
Dec. 30, 1997 |
| 5699981 |
Aircraft cavity acoustic resonance suppression system |
Dec. 23, 1997 |
| 5693918 |
Active exhaust silencer |
Dec. 2, 1997 |
| 5692702 |
Active control of tone noise in engine ducts |
Dec. 2, 1997 |
| 5677958 |
Active sound damper |
Oct. 14, 1997 |
| 5618010 |
Active noise control using a tunable plate radiator |
Apr. 8, 1997 |
| 5619020 |
Muffler |
Apr. 8, 1997 |
| 5600106 |
Actively sound reduced muffler having a venturi effect configuration |
Feb. 4, 1997 |
| 5590849 |
Active noise control using an array of plate radiators and acoustic resonators |
Jan. 7, 1997 |
| 5574264 |
Active exhaust-noise attenuation muffler |
Nov. 12, 1996 |
| 5550334 |
Actively sound reduced muffler having a venturi effect configuration |
Aug. 27, 1996 |
| 5541373 |
Active exhaust silencer |
Jul. 30, 1996 |
| 5507151 |
Noise reduction in screw compressor-based refrigeration systems |
Apr. 16, 1996 |
| 5498127 |
Active acoustic liner |
Mar. 12, 1996 |
| 5466899 |
Arrangement for active sound damping |
Nov. 14, 1995 |
| 5466899 |
Arrangement for active sound damping |
Nov. 14, 1995 |
| 5455396 |
Temperature/environment-resistant transducer suspension |
Oct. 3, 1995 |
| 5446249 |
Dry acoustic system preventing condensation |
Aug. 29, 1995 |
| 5445517 |
Adaptive noise silencing system of combustion apparatus |
Aug. 29, 1995 |
| 5446790 |
Intake sound control apparatus |
Aug. 29, 1995 |
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