Noise Canceler

• US 5,754,665 A
• Filed: 06/20/1997
• Issued: 05/19/1998
• Est. Priority Date: 02/27/1995
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hosoi, Yoshiaki
• Primary Examiner(s): Harvey, Minsun Oh
• Application Number:
  US08/879,907
• Time in Patent Office: 333 Days
• Field of Search: 381/71, 381/94.1, 381/93, 381/72, 381/168, 381/92, 381/94.7, 379/387, 379/390, 379/395, 379/437, 379/419
• US Class Current: 381/94.1
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

The object of the noise canceler of the present invention is to allow hands-free conversation from either of two microphones through a parallel construction having two noise cancelers using FIR adaptive filters. When microphone 2 (at the driver'"'"'s seat) is used for conversation, microphone 3 (at the passenger seat) is used for collecting noise and a noise-reduced voice signal 105 is obtained by using FIR adaptive filter 14; and when microphone 3 is used for conversation, microphone 2 is used for collecting noise and a noise-reduced voice signal 104 is obtained using FIR adaptive filter 13. These two voice signals 104, 105 are added at adder 17 and the result outputted as voice output signal 103.

Claims

1. An adaptive control noise canceler system for a voice communication installation having first and second spaced microphones (2,3), either of which may receive a voice input from a speaker or a background noise input, said system comprising:

a) a first signal channel including, in series connection, a first A/D converter (11) having an input connected to the first microphone, a first FIR adaptive filter (13), and a first adder (15),

b) a second signal channel including, in series connection, a second A/D converter (12) having an input connected to the second microphone, a second FIR adaptive filter (14), and a second adder (16),

c) circuit means coupling an output of the first A/D converter to the second adder, and an output of the second A/D converter to the first adder,

d) feedback means coupling an output of the first adder to an input of the first filter, and an output of the second adder to an input of the second filter, and

e) a third adder (17) for combining the outputs of the first and second adders,

f) wherein when the first microphone receives a voice input the second microphone serves as a noise detector, and vice versa.

2. A system according to claim 1, wherein the first and second microphones are disposed on a driver side and a passenger side of a motor vehicle, respectively.

3. A system according to claim 1, further comprising a D/A converter (18) having an input connected to an output of said third adder (17).