Method and a hearing device for improved separability of target sounds

Patent metadata

Field	Value
Publication number	US-10560790-B2
Application number	US-201715634465-A
Country	US
Kind code	B2
Filing date	Jun 27, 2017
Priority date	Jun 27, 2016
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A hearing device, a hearing system and a method for improving a hearing impaired person's ability to perceptually separate a target sound from competing sounds, the target sound and the competing sounds forming a composite sound signal having a given frequency range, where the method comprises the steps of: (i) subdividing the frequency range of the composite sound signal into a plurality of frequency sub-bands; (ii) grouping frequency sub-bands based on comparable characteristics of the plurality of frequency sub-bands; (iii) for each of the groups calculating a group envelope; and (iv) multiplying the signal in the frequency sub-bands of each individual group by a function or functions that enhance(s) peaks of the group envelope and/or attenuates energy in troughs in the group envelope. The comparable characteristics may be the correlation between the envelope of each of the bands in the specific group of frequency sub-bands and the corresponding group envelope.

First claim

The invention claimed is:

1. A hearing device for improving a hearing impaired user's ability to perceptually separate a target sound from competing sounds, the target sound and the competing sounds forming a composite sound signal having a given frequency range, the hearing device comprising
an input unit for providing a time-domain electric input signal y(n) as digital samples representing said composite sound signal in a frequency range of operation forming part of said given frequency range, n being a time-sample index,
an analysis filter bank subdividing said frequency range of operation, or a part thereof, of said composite sound signal into a plurality of frequency sub-bands and providing corresponding frequency sub-band signals;
a signal processor connected to said analysis filter bank and configured to
arrange frequency sub-bands in sub-band-groups based on comparable characteristics among the plurality of frequency sub-band signals;
calculate a group envelope for each of said sub-band groups, said group envelope comprising peaks and troughs;
provide an enhancement function for each sub-band group configured to enhances said peaks in the group envelope and/or attenuate said troughs in the group envelope; and
multiply a signal in the frequency sub-bands of each individual sub-band-group by a respective enhancement function for the sub-band group in question, or a scaled version thereof, to provide enhanced frequency sub-band signals.

2. A hearing device according to claim 1 wherein the signal processor is further configured to apply a frequency and/or level dependent gain or attenuation and/or other signal processing algorithms to said frequency sub-band signals or to said enhanced frequency sub-band signals to provide processed frequency sub-band signals.

3. A hearing device according to claim 1 comprising a synthesis filter bank for converting said processed frequency sub-band signals to a time-domain electric output signal.

4. A hearing device according to claim 3 comprising an output unit for converting said time-domain electric output signal to stimuli perceivable by the user as sound.

5. A hearing device according to claim 1 comprising a hearing aid, a headset, an earphone, an ear protection device or a combination thereof.

6. A hearing system comprising
a hearing device according to claim 1 ; and
an auxiliary device, wherein the hearing system is adapted to establish a communication link between the hearing device and the auxiliary device to provide that information can be exchanged or forwarded from one to the other.

7. A hearing system according to claim 6 wherein the auxiliary device is or comprises an audio gateway device, a remote control for controlling functionality and operation of the hearing device(s), a smartphone or a combination thereof.

8. A hearing system according to claim 6 configured to run an APP allowing to control functionality of the hearing system via the auxiliary device.

9. A method for improving a hearing impaired person's ability to perceptually separate a target sound from competing sounds, the target sound and the competing sounds forming a composite sound signal having a given frequency range, the method comprising
providing a time-domain electric input signal y(n) as digital samples representing said composite sound signal in a frequency range of operation forming part of said given frequency range, n being a time-sample index,
subdividing said frequency range of operation, or a part thereof, of said composite sound signal into a plurality of frequency sub-band;
arranging frequency sub-bands in sub-band-groups based on comparable characteristics among the plurality of frequency sub-bands;
calculating a group envelope for each of said sub-band groups, said group envelope comprising peaks and troughs; and
multiplying a signal in the frequency sub-bands of each individual sub-band-group by a function that enhances said peaks of the group envelope and/or attenuates said troughs in the group envelope, thereby providing an enhancement envelope for each of said sub-band-groups.

10. Method according to claim 9 , wherein said comparable characteristic comprises the correlations among the signal envelopes in said multiple frequency sub-bands.

11. A method according to claim 9 , comprising the steps of:
for each of said frequency sub-bands calculate the envelope of the band;
for each of the sub-band-groups calculate the correlation between the envelope of each of the frequency sub-bands in the specific sub-band-group and the corresponding group envelope;
for each of the sub-band groups calculate the enhancement envelope for each frequency sub-band in the sub-band-group in question; and
for each frequency sub-band multiply the signal in the band with the enhancement envelope of the band.

12. A method according to claim 9 comprising the steps of:
calculate the correlation between the envelopes of each of said frequency sub-bands, thereby providing a correlation matrix C;
based on said correlation matrix C group the frequency sub-bands into said sub-band-groups; and
calculate a group envelope for each of the sub-band-groups.

13. A method according to claim 9 , wherein said grouping comprises the following steps:
defining a threshold for correlation C_thr;
selecting the row of the correlation matrix C that has the highest sum of supra-threshold values; and
designating the frequency sub-bands for which correlations in the selected row are greater than C_thr as the members of a first sub-band-group.

14. A method according to claim 13 , wherein said grouping further comprises
setting the elements in the rows and columns of the correlation matrix C corresponding to the frequency sub-bands of said first sub-band-group equal to zero, thereby providing a modified correlation matrix C M ;
selecting the row of the modified correlation matrix C M that has the highest sum of suprathreshold correlations; and
designating the frequency sub-bands for which correlations in the selected row are greater than C_thr as members of a second sub-band-group.

15. A method according to claim 9 wherein said enhancement of peaks of the group envelope and attenuation of troughs in the group envelope comprises the following steps:
defining a modulation enhancement m_enh;
for the defined modulation enhancement (m_enh) keeping a running tally of the group envelope's mean value, modulation depth m_group and the current amplitude offset at time n relative to said mean value, where the modulation depth is given by m_group;
for each frequency sub-band in each respective sub-band-group:
multiplying the signal in a current time window by (1+p(n)*c(n)*m_enh), where 0≤p(n)≤1, and where p(n) is a function of the band envelope's correlation with the group envelope.

16. A method according to claim 9 wherein said modulation enhancement m_enh is divided in two enhancement parts, one that controls the extent of peak enhancement and one that controls the extent of deepening of troughs.

17. A method according to claim 9 , wherein said comparable characteristics are fundamental frequencies F 0k in the amplitude variation of each separate frequency sub-band, where k is a frequency sub-band index.

18. A data processing system comprising a processor and program code means for causing the processor to perform the method of claim 9 .

19. A hearing device for improving a hearing impaired user's ability to perceptually separate a target sound from competing sounds, where the hearing device comprises a data pr

Assignees

• Oticon As

Inventors

• Jones Gary

Classifications

• H04R2225/43

  Signal processing in hearing aids to enhance the speech intelligibility · CPC title

• H04R25/554

  using a wireless connection, e.g. between microphone and amplifier or using Tcoils · CPC title

• H04R25/505 Primary

  using digital signal processing · CPC title

• H04R2430/03

  Synergistic effects of band splitting and sub-band processing · CPC title

• G10L21/0332

  involving modification of waveforms · CPC title