Noise reducing microphone apparatus

• US 5,917,921 A
• Filed: 04/17/1995
• Issued: 06/29/1999
• Est. Priority Date: 12/06/1991
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ohkubo, Masashi, Sasaki, Tooru
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): LEE, PING
• Application Number:
  US08/424,581
• Time in Patent Office: 1,534 Days
• Field of Search: 381/94, 381/92, 381/71, 381/68, 381/68.2, 381/68.4
• US Class Current: 381/94.1
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A noise reducing microphone apparatus having an adaptive noise canceller which has a primary input and a reference input and in which the reference input is subtracted from the primary input through an adaptive filter and the adaptive filter is adaptively controlled by an output signal resulted from the subtraction, comprises. The apparatus includes a pair of microphone units disposed in proximate locations; and subtracting means for performing subtraction of outputs from the pair of microphone units. An output from one of the microphone units is supplied as the primary input of the adaptive noise canceller. A differential output from the subtracting means is supplied as the reference input of the adaptive noise canceller.

Claims

1. A noise reducing microphone apparatus for reducing effects of wind noise on desired sounds comprising:

an adaptive noise canceller which has a primary input signal representing the desired sounds and the wind noise and a reference input signal representing only the wind noise and in which the reference input signal is passed through an adaptive filter and subtracted from the primary input signal and the adaptive filter is adaptively controlled by an output signal resulting from the subtraction;

a pair of microphone units disposed in close proximity to each other and each receiving the desired sounds and the wind noise, the output of one of the microphone units being supplied as the primary input signal to the adaptive noise canceller;

a single vibration detector for generating a vibration signal proportional to vibration affecting the pair of microphone units; and

adding and subtracting means for performing subtraction of output signals from the pair of microphone units and performing addition of said vibration signal to a result of the subtraction and producing an output supplied as the reference input signal to the adaptive noise canceller,

wherein an output from one of the microphone units is supplied as the primary input signal to said adaptive noise canceller and an output signal from the adding and subtracting means is supplied as the reference input signal to the adaptive noise canceler so that an output of the adaptive noise canceller has reduced wind noise effects.

2. The noise reducing microphone apparatus according to claim 1, further comprising:

a plurality of analog-to-digital converters receiving outputs respectively from the pair of microphone units and the vibration detecting means for producing digital outputs fed to the adaptive noise canceller and the adding and subtracting means; and

a digital-to-analog converter receiving the output of the adaptive noise canceller and producing an analog output signal therefrom.

3. The noise reducing microphone apparatus according to claim 1, further comprising:

a first analog-to-digital converter receiving the output of the one microphone unit and producing a digital signal fed to the adaptive noise canceller as the primary input signal;

a second analog-to-digital converter receiving the output of the adding and subtracting means and producing a digital signal fed to the adaptive noise canceller as the reference input signal; and

a digital-to-analog converter receiving the output of the adaptive noise canceller and producing an analog output signal therefrom.