Hearing Implant Bilateral Matching of ILD Based on Measured ITD

• US 20160165363A1
• Filed: 12/02/2015
• Published: 06/09/2016
• Est. Priority Date: 12/03/2014
• Status: Active Grant

• Current Assignee: MED-EL Elektromedizinische Gerate GmbH (MED-EL Corporation)
• Original Assignee: MED-EL Elektromedizinische Gerate GmbH (MED-EL Corporation)
• Inventors: Meister, Dirk, Schleich, Peter
• Granted Patent: US 9,693,155 B2
• Time in Patent Office: Days
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: H04R 25/552 Binaural

Abstract

Arrangements are described for generating electrode stimulation signals for stimulation contacts in implanted electrode arrays of a bilateral hearing implant system having electrode arrays on both the left- and right-sides. Left-side and right-side audio input signals are processed to generate corresponding left-side and right-side band pass signals, which each represent an associated band of audio frequencies in the audio input signal. Frequency-specific interaural time delays (ITDs) are estimated for the band pass signals, and the estimated ITDs are used to adjust interaural level differences (ILDs) in the band pass signals. The adjusted band pass signals then are used to generate left-side and right-side electrode stimulation signals for the stimulation contacts in the corresponding left-side and right-side electrode arrays.

Claims

1. A bilateral hearing implant system comprising:

implanted left-side and right-side electrode arrays, each with a plurality of stimulation contacts for delivering electrode stimulation signals to adjacent auditory neural tissue;

left- and right-side filter banks configured to process left- and right-side audio input signals to generate corresponding left- and right-side pluralities of band pass signals, wherein each band pass signal represents an associated band of audio frequencies in the audio input signal;

an interaural time delay (ITD) processing module configured to;

i. estimate ITDs for the band pass signals, and

ii. use the estimated ITDs to adjust interaural level differences (ILDs) in the band pass signals; and

a plurality of audio processing stages configured to use the adjusted band pass signals to generate left-side and right-side electrode stimulation signals for the stimulation contacts in the corresponding left-side and right-side electrode arrays.

2. The system according to claim 1, wherein the ITD processing module is configured to use the audio input signals to estimate the ITDs.

3. The system according to claim 1, wherein the ITD processing module is configured to use the band pass signals to estimate the ITDs.

4. The system according to claim 3, wherein the ITD processing module is configured to use envelope components of the band pass signals to estimate the ITDs.

5. The system according to claim 3, wherein the ITD processing module is configured to use fine structure components of the band pass signals to estimate the ITDs.

6. The system according to claim 1, wherein the ITD processing module is configured to use stimulation pulse requests to estimate the ITDs.

7. The system according to claim 1, wherein the ITD processing module adjusts channel-specific ILDs of the band pass signals.

8. The system according to claim 1, wherein the ITD processing module adjusts broadband ILDs of the band pass signals.

9. The system according to claim 1, wherein the ITD processing module adjusts channel-specific dynamic components in the signals.

10. The system according to claim 1, wherein the ITD processing module is configured to calculate an ITD histogram from overlapping measurement time windows to estimate the ITDs.

11. The system according to claim 11, wherein the ITD processing module is configured to use a standard deviation of the ITD histogram to characterize accuracy of the estimated ITDs and to use a function of estimation accuracy to adjust the ILDs.

12. The system according to claim 12, wherein the ITD processing module is configured to use an estimation accuracy threshold to determine when to adjust the ILDs such that an ILD is adjusted when estimation accuracy of the corresponding ITD is less than the estimation accuracy threshold, but the ILD is not adjusted when estimation accuracy of the corresponding ITD is greater than the estimation accuracy threshold.

13. A method of generating electrode stimulation signals for stimulation contacts in implanted electrode arrays of a bilateral hearing implant system having a left-side electrode array and a right-side electrode array, the method comprising:

processing left-side and right-side audio input signals to generate corresponding left-side and right-side pluralities of band pass signals, wherein each band pass signal represents an associated band of audio frequencies in the audio input signal;

estimating frequency-specific interaural time delays (ITDs) for the band pass signals;

using the estimated ITDs to adjust interaural level differences (ILDs) in the band pass signals; and

using the adjusted band pass signals to generate left-side and right-side electrode stimulation signals for the stimulation contacts in the corresponding left-side and right-side electrode arrays.

14. The method according to claim 13, wherein the audio input signals are used for estimating the ITDs.

15. The method according to claim 13, wherein the band pass signals are used for estimating the ITDs.

16. The method according to claim 15, wherein envelope components of the band pass signals are used for estimating the ITDs.

17. The method according to claim 15, wherein fine structure components of the band pass signals are used for estimating the ITDs.

18. The method according to claim 13, wherein stimulation pulse requests are used for estimating the ITDs.

19. The method according to claim 13, wherein the adjusted ILDs are channel-specific ILDs.

20. The method according to claim 13, wherein the adjusted ILDs are broadband ILDs.

21. The method according to claim 13, wherein adjusting ILDs in the band pass signals includes adjusting channel-specific dynamic components in the signals.

22. The method according to claim 13, wherein the ITDs are estimated using an ITD histogram calculated from overlapping measurement time windows.

23. The method according to claim 22, wherein a standard deviation of the ITD histogram is used to characterize accuracy of the estimated ITDs and a function of estimation accuracy is used for adjusting the ILDs.

24. The method according to claim 23, wherein an estimation accuracy threshold is used to determine when to adjust the ILDs such that an ILD is adjusted when estimation accuracy of the corresponding ITD is less than the estimation accuracy threshold, but the ILD is not adjusted when estimation accuracy of the corresponding ITD is greater than the estimation accuracy threshold.