Methods and apparatuses for setting a hearing aid to an omnidirectional microphone mode or a directional microphone mode

1. A method of automatic switching between a first microphone mode and a second microphone mode in a binaural hearing aid, the binaural hearing aid comprising a processing unit, a first microphone system for provision of a first input signal, and a second microphone system for provision of a second input signal, where the first microphone system is configured for use by a first ear of a user, and the second microphone system is configured for use by a second ear of the user, the method comprising:

obtaining modulations of the first input signal and the second input signal;

determining a first evaluation index of speech intelligibility for the first input signal using a processing unit;

determining a second evaluation index of speech intelligibility for the second input signal;

determining whether one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility; and

setting one or both of the first microphone system and the second microphone system based on a result from the act of determining whether the one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility, wherein the act of setting is performed by the binaural hearing aid;

wherein the act of setting comprises setting one of the first microphone system and the second microphone system to the first microphone mode, and setting the other one of the first microphone system and the second microphone system to the second microphone mode, the second microphone mode being different from the first microphone mode.

2. The method of claim 1 , wherein the modulations comprise spectral modulations.

3. The method of claim 2 , wherein the modulations also comprise temporal modulations.

4. The method of claim 1 , wherein the modulations comprise temporal modulations.

5. The method of claim 1 , wherein the first microphone mode comprises a directional microphone mode.

6. The method of claim 1 , wherein the first microphone mode comprises an omni directional microphone mode.

7. The method of claim 1 , wherein the act of setting comprises setting one or both of the first microphone system and the second microphone system to the first microphone mode when a result of processing the first evaluation index and the second evaluation index indicates low speech intelligibility, the first microphone mode being a directional microphone mode.

8. The method of claim 1 , wherein the act of setting comprises:

setting one of the first microphone system and the second microphone system with a corresponding one of the first evaluation index and the second evaluation index indicating highest speech intelligibility to an omnidirectional microphone mode, and

setting the other one of the first microphone system and the second microphone system with a corresponding one of the first evaluation index and the second evaluation index indicating lowest speech intelligibility to a directional microphone mode.

9. The method of claim 1 , wherein the second microphone mode comprises an omnidirectional microphone mode.

10. The method of claim 1 , wherein the first evaluation index of speech intelligibility is selected from the group consisting of: a speech transmission index (STI), a modified speech transmission index (mSTI), a spectral temporal modulation index (STMI), a modified temporal modulation index (mSTMI), an articulation index (AI), and a modified articulation index (mAI).

11. A method of automatic switching between a first microphone mode and a second microphone mode in a binaural hearing aid, the binaural hearing aid comprising a processing unit, a first microphone system for provision of a first input signal, and a second microphone system for provision of a second input signal, where the first microphone system is configured for use by a first ear of a user, and the second microphone system is configured for use by a second ear of the user, the method comprising:

obtaining modulations of the first input signal and the second input signal;

determining a first evaluation index of speech intelligibility for the first input signal using a processing unit;

determining a second evaluation index of speech intelligibility for the second input signal;

determining whether one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility; and

setting one or both of the first microphone system and the second microphone system based on a result from the act of determining whether the one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility, wherein the act of setting is performed by the binaural hearing aid;

wherein the act of obtaining the modulations of the first input signal and the second input signal is performed with one of the first microphone system and the second microphone system being in the first microphone mode, and the other one of the first microphone system and the second microphone system being in the second microphone mode, the second microphone mode being different from the first microphone mode.

12. The method of claim 11 , wherein the first microphone mode comprises an omni directional microphone mode.

13. The method of claim 11 , wherein the modulations comprise spectral modulations.

14. The method of claim 13 , wherein the modulations also comprise temporal modulations.

15. The method of claim 11 , wherein the modulations comprise temporal modulations.

16. The method of claim 11 , wherein the act of setting comprises setting the first microphone system to a directional microphone mode.

17. The method of claim 11 , wherein the act of setting comprises setting the first microphone system to an omni directional microphone mode.

18. The method of claim 11 , wherein the act of setting comprises setting one or both of the first microphone system and the second microphone system to a directional microphone mode when a result from the acts of determining indicates low speech intelligibility.

19. The method of claim 11 , wherein the act of setting comprises:

setting one of the first microphone system and the second microphone system with a corresponding one of the first evaluation index and the second evaluation index indicating highest speech intelligibility to an omnidirectional microphone mode, and

setting the other one of the first microphone system and the second microphone system with a corresponding one of the first evaluation index and the second evaluation index indicating lowest speech intelligibility to a directional microphone mode.

20. The method of claim 11 , wherein the first evaluation index of speech intelligibility is selected from the group consisting of: a speech transmission index (STI), a modified speech transmission index (mSTI), a spectral temporal modulation index (STMI), a modified temporal modulation index (mSTMI), an articulation index (AI), and a modified articulation index (mAI).

21. A binaural hearing aid comprising:

at least one signal processor;

a first microphone system for provision of a first input signal;

a second microphone system for provision of a second input signal, where the first microphone system is adapted to be placed in or at a first ear of a user, and the second microphone system is adapted to be placed in or at a second ear of the user;

wherein the at least one signal processor is configured for:

obtaining modulations of the first input signal and the second input signal,

determining a first evaluation index of speech intelligibility for the first input signal,

determining a second evaluation index of speech intelligibility for the second input signal,

determining whether one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility; and

setting one or both of the first microphone system and the second microphone system based on a result from the act of determining whether the one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility;

wherein the at least one signal processor is configured for setting one of the first microphone system and the second microphone system to a first microphone mode, and setting the other one of the first microphone system and the second microphone system to a second microphone mode that is different from the first microphone mode.

22. The binaural hearing aid of claim 21 , wherein the modulations comprise spectral modulations.

23. The binaural hearing aid of claim 22 , wherein the modulations also comprise temporal modulations.

24. The binaural hearing aid of claim 21 , wherein the modulations comprise temporal modulations.

25. The binaural hearing aid of claim 21 , wherein the at least one signal processor is configured for setting the first microphone system to a directional microphone mode.

26. The binaural hearing aid of claim 25 , wherein the at least one signal processor is configured for setting the first microphone system to an omni directional microphone mode.

27. The binaural hearing aid of claim 21 , wherein the at least one signal processor is configured for setting one or both of the first microphone system and the second microphone system to a directional microphone mode when a result of processing the first evaluation index and the second evaluation index indicates low speech intelligibility.

28. The binaural hearing aid of claim 21 , wherein the at least one signal processor is configured for:

setting one of the first microphone system and the second microphone system with a corresponding one of the first evaluation index and the second evaluation index indicating highest speech intelligibility to an omnidirectional microphone mode, and

setting the other one of the first microphone system and the second microphone system with a corresponding one of the first evaluation index and the second evaluation index indicating lowest speech intelligibility to a directional microphone mode.

29. The binaural hearing aid of claim 21 , wherein the at least one signal processor is configured for obtaining the modulations of the first input signal and the second input signal with at least one of the first microphone system and the second microphone system being in an omnidirectional microphone mode.

30. The binaural hearing aid of claim 21 , wherein the first evaluation index of speech intelligibility is selected from the group consisting of: a speech transmission index (STI), a modified speech transmission index (mSTI), a spectral temporal modulation index (STMI), a modified temporal modulation index (mSTMI), an articulation index (AI), and a modified articulation index (mAI).

31. A binaural hearing aid comprising:

at least one signal processor;

a first microphone system for provision of a first input signal;

a second microphone system for provision of a second input signal, where the first microphone system is adapted to be placed in or at a first ear of a user, and the second microphone system is adapted to be placed in or at a second ear of the user;

wherein the at least one signal processor is configured for:

obtaining modulations of the first input signal and the second input signal,

determining a first evaluation index of speech intelligibility for the first input signal,

determining a second evaluation index of speech intelligibility for the second input signal,

determining whether one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility; and

setting one or both of the first microphone system and the second microphone system based on a result from the act of determining whether the one or more criterions are met by the first evaluation index of speech intelligibility and the second evaluation index of speech intelligibility;

wherein the at least one signal processor is configured for obtaining the modulations of the first input signal and the second input signal is performed with one of the first microphone system and the second microphone system being in a first microphone mode, and the other one of the first microphone system and the second microphone system being in a second microphone mode that is different from the first microphone mode.