Claims
- 1. A hearing aid comprising
a front microphone for outputting a front signal Xfront; a back microphone for outputting a back signal Xback; a delay processor adapted for processing said front signal and said back signal according to a parametric input and for outputting a directionally processed signal according to the formula:Y=Xfront*(1−omni*e−jωT)+Xback*(omni−e−jωT)where T is a predetermined acoustic delay; a signal processor for processing said directionally processed signal; and a parameter control means for estimating said directionally processed signal and for setting a value of the parameter omni suitable for minimizing said directionally processed signal.
- 2. The hearing aid according to claim 1, wherein said parameter control means is adapted for controlling the parameter omni within the range from minus 1.5 to plus 1.0.
- 3. The hearing aid according to claim 1, wherein said parameter control means is adapted for controlling the parameter omni to achieve a pair of null directions, symmetrical about the 180° direction.
- 4. The hearing aid according to claim 1, wherein said parameter control means is adapted for minimizing said directionally processed signal by applying an LMS-algoritm.
- 5. The hearing aid according to claim 1, wherein said delay processor comprises
a set of frequency band filters for splitting said front signal and said back signal into respective input channel signals; a set of channel delay processors for separately processing respective input channel signals according to respective channel parameters and for outputting respective directionally processed channel signals; a set of parameter controllers for separately processing respective directionally processed channel signals and ouputting respective channel parameters; and a combining unit for combining said directionally processed channel signals to provide said directionally processed signal.
- 6. The hearing aid according to claim 1, wherein said signal processor is adapted for processing said directionally processed signal for compensation of a hearing impairment.
- 7. A hearing aid comprising
a front microphone for outputting a front signal Xfront; a back microphone for outputting a back signal Xback; a set of frequency band filters for splitting said front signal and said back signal into a set of front input channel signals and a set back channel signals; a set of channel delay processors for separately processing said front input channel signals and said back input channel signals according to respective parametric inputs and for outputting a set of directionally processed channel signals, each according to the formula:Y=Xfront*(1−omni*e−jωT)+Xback*(omni−e−jωT)where omni is a parameter of a respective channel and T is a predetermined acoustic delay; a set of parameter controllers for separately processing respective directionally processed channel signals and ouputting respective channel parameters; and a combining unit for combining said directionally processed channel signals to provide a combined directionally processed signal.
- 8. A method of controlling a hearing aid, comprising
processing in a delay processor signals from at least a front microphone and a back microphone according to a parametric input omni for outputting a directionally processed signal according to the formula:Y=Xfront*(1−omni*e−jωT)+Xback*(omni−e−jωT)where T is a predetermined acoustic delay; estimating said directionally processed signal; and setting a value of the parameter omni suitable for minimizing said directionally processed signal.
- 9. The method according to claim 8, comprising controlling the parameter omni within the range from 1.0 to −1.5.
- 10. The method according to claim 8, comprising controlling the parameter omni to achieve a pair of null directions, symmetrical about the 180° direction.
- 11. The method according to claim 8, comprising minimizing the the output signal from the delay processor by applying an LMS-algoritm.
- 12. The method according to claim 8, comprising splitting the input signals into separate frequency bands, and processing the band-limited signals with respective channel delay processors and parameter controllers to minimize the output signals in respective frequency bands.
- 13. The method according to claim 12, comprising combining the signals from the respective channel delay processors; and processing said directionally processed signal for compensation of a hearing impairment.
- 14. A noise reduction system for a hearing aid, comprising
a directional controller capable of adjusting the sound receptive property of the microphone system to change, according to a control parameter, between an omnidirectional characteristic, a directional characteristic and a directional characteristic with moving null-directions; and an adaptive controller adapted for automatically adjusting the control parameter so as to move a null-direction to reduce the noise signal.
- 15. A method for reducing noise in a hearing aid, comprising:
receiving an acoustical signal in a microphone system, processing outputs of the microphone system in a parameter controlled delay processor adapted for changing, according to a control parameter, between an omnidirectional characteristic, a directional characteristic and a directional characteristic with moving null-directions, and adjusting the parameters that control the delay processor with an adaptive controller so as to minimize the output signal from the delay processor.
Priority Claims (1)
Number |
Date |
Country |
Kind |
PA200100621 |
Apr 2001 |
DK |
|
RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of application No. PCT/DK02/00248, filed on Apr. 12, 2002 in Denmark, now abandoned. The present application is further based on PA 2001 00621, filed on Apr. 18, 2001 in Denmark, the contents of which are incorporated hereinto by reference.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
PCT/DK02/00248 |
Apr 2002 |
US |
Child |
10685541 |
Oct 2003 |
US |