Hearing aid with suppression of wind noise

• US 20070030989A1
• Filed: 08/01/2006
• Published: 02/08/2007
• Est. Priority Date: 08/02/2005
• Status: Active Grant

• Current Assignee: GN Resound A/S (GN Store Nord A/S)
• Original Assignee: GN Resound A/S (GN Store Nord A/S)
• Inventors: Kates, James
• Granted Patent: US 8,019,103 B2
• Time in Patent Office: Days
• US Class Current: 381/317
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 25/502 using analog signal processing
• CPC Class Codes: H04R 25/505 using digital signal processing

Abstract

The present application relates to a hearing aid with suppression of wind noise wherein wind noise detection is provided involving only a single comparison of the input signal power level at first low frequencies with the input signal power level at frequencies that may include the first low frequencies whereby a computational cost effective and simple wind noise detection is provided. The determination of relative power levels of the input signal reflects the shape of the power spectrum of the signal, and the detection scheme is therefore typically capable of distinguishing music from wind noise so that attenuation of desired music is substantially avoided.

Claims

1. A hearing aid comprising

a first microphone for conversion of an acoustic sound signal into a first electronic audio signal,

a first A/D-converter for conversion of the first audio signal into a first digital signal,

a signal processor for digital signal processing of the first digital signal into a digital output signal, including amplification of the first digital signal for compensation of a hearing loss of a wearer of the hearing aid,

a D/A converter for conversion of the digital output signal into an audio output signal, and

a receiver for conversion of the audio output signal into an acoustic audio signal for transmission towards the eardrum of the wearer of the hearing aid, wherein

the signal processor is further adapted to determine the ratio between the input signal power at first low frequencies and the input signal power at frequencies including frequencies different from the first low frequencies whereby presence of wind noise is detected.

2. The hearing aid according to claim 1, wherein the signal processor is a multi-band signal processor.

3. The hearing aid according to claim 2, wherein the first low frequencies constitute the lowest hearing loss signal processing frequency band of the signal processor.

4. The hearing aid according to claim 1, wherein the signal processor is further adapted to determine the ratio between the input signal power at first low frequencies and the input signal power of the bandwidth of the signal processor including the first low frequencies.

5. The hearing aid according to claim 1, wherein the signal processor is further adapted to attenuate the first electronic audio signal at second low frequencies in response to the determined ratio whereby suppression of wind noise is provided.

6. The hearing aid according to claim 5, wherein the signal processor is a multi-band signal processor and the second low frequencies constitute the two lowest hearing loss signal processing frequency bands of the signal processor.

7. The hearing aid according to claim 5, wherein the signal processor is a multi-band signal processor and the signal processor is adapted to attenuate the lowest hearing loss signal processing frequency band signal when the ratio is larger than a threshold.

8. The hearing aid according to claim 1, further comprising a second microphone with an output connected to a second A/D converter with an output connected to a delay with an output connected to the signal processor, wherein the signal processor is further adapted to subtract the delayed signal from the first digital signal for provision of a hearing aid with a directional characteristic and to attenuate the delayed signal in response to detection of wind noise whereby suppression of wind noise is provided.

9. The hearing aid according to claim 2, wherein the frequency bands applied in wind noise detection are different from the hearing loss signal processing frequency bands applied in the signal amplification for hearing loss compensation.

10. The hearing aid according to claim 2, wherein hearing loss signal processing frequency bands are provided utilising warped filters.

11. The hearing aid according to claim 10, wherein the warped filters comprise cosine-modulated filters.

12. A wind noise compensation method in a hearing aid, comprising the steps of converting sound into an electrical input signal,

determining the ratio between the input signal power at first low frequencies and the input signal power at frequencies including frequencies different from the first low frequencies,

attenuating the signal in second low frequencies when the ratio is larger than a threshold,

amplifying the resulting electrical signal for compensation of the hearing impairment in question, and

converting the amplified signal to sound.