Noise-reducing directional microphone ARRAYOCO
US9202475B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 2012 |
| Grant date | Dec 1, 2015 |
| Priority date | — |
| Expiry date | Oct 15, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2410/07
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In one embodiment, a directional microphone array having (at least) two microphones mounted on opposite sides of a device generates forward and backward base signals from two (e.g., omnidirectional) microphone signals using diffraction filters and equalization filters. Each diffraction filter implements a (possibly different) transfer function representing the response of an audio signal traveling from a corresponding microphone around the device to the other microphone. A scale factor is applied to, for example, the backward base signal, and the resulting scaled backward base signal is combined with (e.g., subtracted from) the forward base signal to generate a first-order differential audio signal. After low-pass filtering, spatial noise suppression can be applied to the first-order differential audio signal. Microphone arrays having one (or more) additional microphones can be designed to generate second- (or higher-) order differential audio signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.