Hearing aid

• US 5,867,581 A
• Filed: 10/11/1995
• Issued: 02/02/1999
• Est. Priority Date: 10/14/1994
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Obara, Kazuaki
• Primary Examiner(s): LE, HUYEN D
• Application Number:
  US08/540,872
• Time in Patent Office: 1,210 Days
• Field of Search: 381/68, 381/68.2, 381/68.4, 381/56, 381/57, 381/94, 381/104, 381/107, 381/109, 381/110, 381/92, 381/94.2, 381/312, 381/313, 381/320, 381/321, 381/122
• US Class Current: 381/312
• CPC Class Codes: H04R 2225/43 Signal processing in hearing aids to enhance the speech intelligibility
• CPC Class Codes: H04R 2225/61 Aspects relating to mechanical or electronic switches or control elements, e.g. functioning
• CPC Class Codes: H04R 25/505 using digital signal processing

Abstract

According to a hearing aid comprising a voiceless period information detecting means for detecting information about a voiceless period based on sound received by a sound input means, and a control means for changing an amplification factor of an amplifying means or switching on/off output of sound emitted by a sound output means based on the sound received by the sound input means and the information about the voiceless period, output of the hearing aid can be controlled depending on noise included in the sound.

Moreover, according to a hearing aid comprising a specific sound detecting means for detecting sound having specific frequency from sound received by a sound input means, and control means for changing an amplification factor of an amplifying means or switching on/off output of sound emitted by a sound output means, or making the sound output means receive either a signal passing through a filter for the specific frequency or a signal bypassing the filter, based on the sound having the specific frequency, warning sound having the specific frequency or the like appearing suddenly in ambient sound can be attenuated.

Claims

1. A hearing aid for a wearer receiving sounds comprising:

at least two sound input means for receiving said sounds for producing first signals,

information detecting means for detecting, based on the first signals, whether a front of the wearer is directed to an incoming direction of the sound and producing second signals,

an analyzer to analyze said sounds and determine frequency components of said sounds,

a detector to detect a voiceless period of said sounds,

a subtractor to remove noise from said sounds, said subtractor using a spectrum subtraction technique and producing an intermediate sound,

a spectral converter to change a frequency characteristic of the intermediate sound based on a hearing characteristic of the wearer and the frequency components of said sounds and producing a further intermediate signal,

a synthesizer to synthesize the further intermediate signal using at least one of a discrete fourier transform and a linear predictive coding to produce a synthetic sound,

amplifying means for amplifying the first signals,

sound output means for emitting the sound amplified by said amplifying means, and

control means for automatically changing an amplification factor of said amplifying means as a function of the second signals.

2. A method for aiding the hearing of a wearer receiving sounds comprising the steps of:

(a) receiving said sounds from at least two sound inputs,

(b) producing first signals based on the sounds received in Step (a),

(c) analyzing the sounds received in Step (a) and determining frequency components of the sounds,

(d) detecting a voiceless period of the sounds received in Step (a),

(e) removing noise from the sounds received in Step (a) by using a spectrum subtraction technique and producing an intermediate sound,

(f) changing a frequency characteristic of the intermediate sound based on a hearing characteristic of the wearer and the frequency components of the sounds of step (b1) and producing a further intermediate signal,

(g) synthesizing the further intermediate signal using at least one of a discrete fourier transform and a linear predictive coding to produce a synthetic sound,

(h) detecting whether a front of the wearer is directed to an incoming direction of the sound and producing second signals, based on the first signals,

(i) amplifying the first signals,

(j) emitting the sound amplified by said amplifying means, and

(k) automatically changing an amplification factor of said amplifying means as a function of the second signals.