Active noise control system
US4689821A · kind A · utility
70Cited by
10References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1985 |
| Grant date | Aug 25, 1987 |
| Priority date | — |
| Expiry date | Sep 23, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2210/3216
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An active noise control system reduces cabin noise levels for a propeller or propfan aircraft due to the propeller noise signature by making the output from a secondary noise source identical in amplitude but opposite in phase to the propeller noise signature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.