Hearing aid with improved localization of a monaural signal source
A new hearing aid is provided in which signals that are received from an external device, such as a spouse microphone, a media player, a hearing loop system, a teleconference system, a radio, a TV, a telephone, a device with an alarm, etc., are filtered in such a way that a user can localize the sound source.
1. A hearing aid comprising:
an electronic input for provision of a monaural audio signal in response to a wireless signal received by the hearing aid;
an ITE microphone housing accommodating at least one ITE microphone, the at least one ITE microphone configured to provide an output signal;
a filter for filtering the monaural audio signal and configured to output an output signal, wherein the filter is configured to:
phase shift the monaural audio signal based on the output signal of the at least one ITE microphone, or
apply a gain for the monaural audio signal based on the output signal of the at least one ITE microphone, or
phase shift and apply the gain for the monaural audio signal based on the output signal of the at least one ITE microphone;
a processor configured to generate a hearing loss compensated output signal based on the output signal of the filter, and
a receiver for conversion of the hearing loss compensated output signal into an acoustic signal for transmission towards an eardrum of a user of the hearing aid.
2. The hearing aid according to claim 1 , wherein the processor is configured to calculate a cross-correlation between the monaural audio signal and the output signal of the at least one ITE microphone, and to determine the phase shift based on the calculated cross-correlation.
3. The hearing aid according to claim 1 , wherein the filter is an adaptive digital filter with filter coefficients that are adapted to reduce a difference between the output signal of the at least one ITE microphone and the output signal of the filter.
4. The hearing aid according to claim 1 , wherein the processor is configured for:
determining signal magnitudes of the output signal of the at least one ITE microphone at a plurality of frequencies,
determining signal magnitudes of the monaural audio signal at the plurality of frequencies, and
determining gain values of the filter at respective frequencies of the plurality of frequencies based on the determined signal magnitudes of the output signal of the at least one ITE microphone and the determined signal magnitudes of the monaural audio signal.
5. The hearing aid according to claim 1 , wherein the filter is configured for individually processing the monaural audio signal in a plurality of frequency channels.
6. A binaural hearing aid system comprising the hearing aid of claim 1 .
7. The hearing aid of claim 1 , further comprising an antenna for receiving the wireless signal.
8. The hearing aid of claim 1 , further comprising a telecoil for receiving the wireless signal.
9. The hearing aid of claim 1 , wherein the wireless signal comprises a RF signal.
10. The hearing aid of claim 1 , wherein the wireless signal comprises an electromagnetic signal.
11. The hearing aid of claim 1 , wherein the wireless signal is transmitted from a device that is external to the hearing aid.
12. A hearing aid comprising:
an electronic input for provision of a monaural audio signal in response to a wireless signal received by the hearing aid;
an ITE microphone housing accommodating at least one ITE microphone, the at least one ITE microphone configured to provide an output signal;
a filter for filtering the monaural audio signal and configured to output an output signal, wherein the filter is configured to:
phase shift the monaural audio signal based on the output signal of the at least one ITE microphone, or
apply a gain for the monaural audio signal based on the output signal of the at least one ITE microphone, or
phase shift and apply the gain for the monaural audio signal based on the output signal of the at least one ITE microphone;
a processor configured to generate a hearing loss compensated output signal based on the output signal of the filter, and
a receiver for conversion of the hearing loss compensated output signal into an acoustic signal for transmission towards an eardrum of a user of the hearing aid;
wherein a transfer function of the filter is substantially equal to a left ear part or a right ear part of a Head Related Transfer Function.
13. A hearing aid comprising:
an electronic input for provision of a monaural audio signal in response to a wireless signal received by the hearing aid;
an ITE microphone housing accommodating at least one ITE microphone, the at least one ITE microphone configured to provide an output signal;
a filter for filtering the monaural audio signal and configured to output an output signal, wherein the filter is configured to:
phase shift the monaural audio signal based on the output signal of the at least one ITE microphone, or
apply a gain for the monaural audio signal based on the output signal of the at least one ITE microphone, or
phase shift and apply the gain for the monaural audio signal based on the output signal of the at least one ITE microphone;
a processor configured to generate a hearing loss compensated output signal based on the output signal of the filter, and
a receiver for conversion of the hearing loss compensated output signal into an acoustic signal for transmission towards an eardrum of a user of the hearing aid;
wherein the filter is an adaptive digital filter with filter coefficients that are adapted to reduce a difference between the output signal of the at least one ITE microphone and the output signal of the filter; and
wherein the filter coefficients are adapted towards a solution of:
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wherein
S IEC (f,t) is a short time spectrum at time t of an output signal of the at least one ITE microphone, and
S is a short time spectra at time t of the monaural audio signal,
G(f,t) is a transfer function of the filter,
p is a norm factor, and
W(f) is a frequency weighting factor.
14. The hearing aid according to claim 13 , wherein p=2.
15. A method of processing a monaural signal in a hearing aid having an ITE microphone housing accommodating at least one ITE microphone, the at least one ITE microphone providing an output, the method comprising:
filtering the monaural audio signal, wherein the monaural audio signal is generated at the hearing aid in response to a wireless signal received by the hearing aid, wherein the act of filtering comprises:
phase shifting the monaural audio signal based on the output of the at least one ITE microphone, or
applying a gain for the monaural audio signal based on the output of the at least one ITE microphone, or
phase shifting and applying the gain for the monaural audio signal based on the output of the at least one ITE microphone;
generating a hearing loss compensated output signal based the filtered monaural signal; and
converting the hearing loss compensated output signal into an acoustic signal for transmission towards an eardrum of a user of the hearing aid.
16. The method of claim 15 , wherein the act of filtering is performed using a filter, and wherein a transfer function of the filter is substantially equal to a left ear part or a right ear part of a Head Related Transfer Function.