Active acoustic wall
US6041125A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 19, 1996 |
| Grant date | Mar 21, 2000 |
| Priority date | — |
| Expiry date | Dec 19, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K11/172
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An active acoustic wall has sound-pressure detectors provided within respective cells so that a detected signal acts to oscillate an oscillation plate in the cell. A porous material on a surface is thereby provided with a high sound absorption coefficient over a wide frequency range. A space between a porous material or a perforated plate 1 on the surface and a back material fixed on a back side is divided into a plurality of sections so as to form cells 10 containing an air layer or a porous sound-absorbing material. Oscillation plates 6 are arranged within respective cells 10 so as to be driven for oscillation by oscillation-plate driving units 5. Sound-pressure detectors 7 are provided close to the porous material 1 in the cell 10 so that a detected signal is inputted to a signal-processing unit 8. The signal processing unit 8 outputs a signal to the driving unit 5 for oscillating the oscillation plate 6 such that an output of the sound-pressure detector is minimized. The sound pressure on the surface of the porous material 1 is minimized at all frequencies. The velocity of particles on the surface becomes large so that the particles are turned into thermal energy, thereby provi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.