Passive acoustical filters with filled expansion chamber
US9420367B2 · kind B2 · utility
1Cited by
6References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 8, 2015 |
| Grant date | Aug 16, 2016 |
| Priority date | — |
| Expiry date | Jul 8, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R1/1016
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A passive acoustical filter includes a first opening to receive ambient sound, a second opening to output filtered sound, and a first low pass filter element coupled between the first opening and the second opening. The first low pass filter element includes a first expansion chamber filled with a material in which a speed of sound is lower than a speed of sound in air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.