Method for operating a hearing instrument and hearing instrument
A method operates a hearing instrument having an acousto-electric first input transducer and an electro-acoustic output transducer. A first input signal is generated by the first input transducer from an ambient sound. The first input signal and/or a first intermediate signal derived from the first input signal is resolved into a multiplicity of frequency bands. An output signal is generated from the first input signal, or from the first intermediate signal, by frequency-selective signal processing. A relevant subset of frequency bands is determined from the aforementioned multiplicity such that, in each frequency band of the relevant subset, an output sound generated from the output signal by the output transducer makes a contribution that lies above a predefined or desired threshold, further, with the aid of signal components of the first input signal, or of the first intermediate signal.
1. A method for operating a hearing instrument having at least one acousto-electric first input transducer and an electro-acoustic output transducer, which comprises the steps of:
generating a first input signal via the at least one acousto-electric first input transducer from an ambient sound;
breaking down the first input signal and/or a first intermediate signal derived from the first input signal into a plurality of frequency bands;
generating an output signal from the first input signal, or from the first intermediate signal, by means of frequency-selective signal processing;
determining a relevant subset of frequency bands from the plurality of frequency bands such that, in each of the frequency bands of the relevant subset, an output sound generated from the output signal by the electro-acoustic output transducer makes a contribution that lies above a defined or desired threshold;
verifying an activation criterion for activation of a subalgorithm for the frequency-selective signal processing only in the frequency bands of the relevant subset with an aid of signal components of the first input signal, or of the first intermediate signal; and
applying the subalgorithm to the first input signal, or to the first intermediate signal, in dependence on the activation criterion.
2. The method according to claim 1 , wherein in order to determine the relevant subset, an adjustment formula for frequency band-based adjustment of the hearing instrument is used.
3. The method according to claim 1 , wherein in order to determine the relevant subset on a frequency band basis, a gain value of signal contributions of the first input signal, or of the first intermediate signal, in a respective one of the frequency bands is used.
4. The method according to claim 3 , wherein in order to determine the gain value on the frequency band basis, the first input signal is compared with the output signal and/or a signal amplification applied along a signal path from the at least one acousto-electric first input transducer to the electro-acoustic output transducer is monitored, and wherein the gain value is compared with a first limit value dependent on the predefined or desired threshold.
5. The method according to claim 1 , wherein in order to determine the relevant subset, a setting of a signal amplification performed by a user of the hearing instrument is taken into account.
6. The method according to claim 1 , wherein in order to verify the activation criterion, a characteristic quantity which provides inference about a noise component in the frequency bands is ascertained from the signal components of the first input signal, or of the first intermediate signal, in the plurality frequency bands of the relevant subset.
7. The method according to claim 6 , which further comprises ascertaining a signal-to-noise ratio of the signal components in the frequency bands of the relevant subset as the characteristic quantity.
8. The method according to claim 6 , wherein the characteristic quantity is compared with a noise limit value which corresponds to an upper limit for a permissible noise component, and wherein the activation criterion for the activation of the subalgorithm is considered to be satisfied if the noise limit value is exceeded.
9. The method according to claim 1 , wherein a second input signal is generated by an acousto-electric second input transducer of the hearing instrument from the ambient sound, wherein the output signal is additionally generated from the frequency-selective signal processing of the second input signal, and wherein the subalgorithm contains directional microphony of the first input signal, or of the first intermediate signal, and of the second input signal and/or of a second intermediate signal derived from the second input signal.
10. The method according to claim 9 , wherein the activation criteria is verified with an aid of signal components of the second input signal, or of the second intermediate signal, only in the frequency bands of the relevant subset.
11. The method according to claim 1 , wherein the subalgorithm comprises:
frequency band-based amplification; and/or
frequency band-based compression; and/or
noise suppression.
12. A hearing instrument, comprising:
at least one acousto-electric first input transducer;
an electro-acoustic output transducer; and
a signal processor, wherein the hearing instrument is adapted to carry out the method according to claim 1 .