# US 9,521,482 B2 · Sound receiving device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,521,482 B2
- Document ID: US9521482B2
- Status: Granted
- Kind: B2
- Application number: 14/395,254
- Filed: 2013-09-30
- Published: 2015-03-26
- Granted: 2016-12-13
- Earliest claimed: 2012-11-08
- Assignees: Guangzhou Ruifeng Audio Technology Corporation Ltd
- Applicants: Guangzhou Ruifeng Audio Technology Corporation Ltd.
- Inventors: Bingqi Hu; Yizhen Wang
- Web page: https://patentgrep.com/patent/US9521482B2

## CPC

- H04R 1/406: {microphones}
- H04R 3/005: {for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407)}
- H04R 2201/403: Linear arrays of transducers
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)

## Abstract

A sound receiving device includes a microphone array, a plurality of time delay circuits and a sound-mixing output device. The microphone array includes a plurality of microphones longitudinally arranged along a straight line in order, an output terminal of each microphone is connected with a time delay circuit, and an output terminal of the time delay circuit is connected to an input terminal of the sound-mixing output device; and an i-th time delay circuit has a delay time Ti defined by adding a (n−i) times of unit time to a delay time of a last time delay circuit. The device can increase the output of the forward acoustic wave actuation, decrease the output of the oblique acoustic wave within a certain frequency bandwidth, and obtain nearly the same directional characteristic at the central frequency and adjacent frequencies.

## Claims

### Claim 1

A sound receiving device configured to receive an acoustic wave, comprising a microphone array designed to have a preset center frequency, a plurality of time delay circuits and a sound-mixing output device, wherein the microphone array comprises a plurality of microphones longitudinally arranged along a straight line, two adjacent microphones in the microphone array are separated with a distance of
1
n
⁢
λ
0
,
where n is the total number of the microphones in the microphone array and λ0 a wavelength defined by a speed of the acoustic wave in the air divided by the preset center frequency that is designed in the microphone array;
in the microphone array, an output terminal of each microphone is connected with a time delay circuit, and an output terminal of the time delay circuit is connected to an input terminal of the sound-mixing output device;
an i-th time delay circuit has a delay time Ti defined by adding a (n−i) times of unit time to a delay time of a last time delay circuit, where said unit time is a time for the acoustic wave with a frequency set at the present center frequency to travel between two adjacent microphones after the acoustic signal axially transmitting into the microphone array, n is the total number of the microphones in the microphone array, and i has a value of 1, 2, 3, . . . , or n; and
the total number n of the microphones in the microphone array is an integer greater than or equal to 3.

### Claim 2 (depends on 1)

The sound receiving device of claim 1, wherein the total number n of the microphones in the microphone array is an even number greater than or equal to 4.