In-ear active noise reduction earphone
US9792893B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2016 |
| Grant date | Oct 17, 2017 |
| Priority date | — |
| Expiry date | Sep 20, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2460/01
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An active noise reduction (ANR) earphone system includes a feedback microphone for detecting noise, feedback circuitry, responsive to the feedback microphone, for applying a digital filter Kfb to an output of the feedback microphone to produce an antinoise signal, an electroacoustic driver for transducing the antinoise signal into acoustic energy, a housing supporting the feedback microphone and the driver near the entrance to the ear canal, and an ear tip for coupling the housing to the external anatomical structures of a first ear of a user and positioning the housing to provide a consistent acoustic coupling of the feedback microphone and the driver to the ear canal of the first ear. The acoustic coupling includes a tube of air defined by the combination of the housing and ear tip, having a length L and effective cross-sectional area A such that the ratio L/A is less than 0.6 m−1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.