Hearing device with transfer function adjusted according to predetermined acoustic environments

1. A method for operating a hearing device having an adjustable transfer function comprising M sub-functions, wherein M is an integer with M≧1, and wherein said transfer function describes how input audio signals generated by an input transducer unit of said hearing device relate to output audio signals to be fed to an output transducer unit of said hearing device, said method comprising the steps of

deriving said input audio signals from a current acoustic environment; and

for each of said M sub-functions:

deriving, on the basis of said input audio signals and for each class of N classes each of which describes a predetermined acoustic environment, a class similarity factor indicative of the similarity of said current acoustic environment with the predetermined acoustic environment described by the respective class, wherein N is an integer with N≧2;

deriving from N predetermined base parameter sets assigned to the respective sub-function and in dependence of said class similarity factors an activity parameter set for the respective sub-function, wherein each of said N base parameter sets assigned to the respective sub-function is assigned to a different class of said N classes;

adjusting the respective sub-function by means of said activity parameter set.

2. The method for operating the hearing device according to claim 1 , with M≧2.

3. The method for operating the hearing device according to claim 1 , wherein the base parameter sets are chosen such that using each of the M base parameter sets assigned to one specific class of said N classes for adjusting the sub-function to which the respective base parameter set is assigned provides for optimized output audio signals, when said current acoustic environment is identical with the predetermined acoustic environment described by that specific class.

4. The method for operating the hearing device according to claim 1 , wherein each of said activity parameter sets comprises a multitude of values, in particular a multitude of numbers.

5. The method for operating the hearing device according to claim 1 , wherein each of said activity parameter sets is a single value, in particular, a single number.

6. The method for operating the hearing device according to claim 1 , comprising the step of

deriving, for each of said N classes, a class weight factor from the corresponding class similarity factor;

wherein, for each of said M sub-functions, said deriving of said activity parameter set comprises weighting each base parameter set assigned to the respective sub-function with the corresponding class weight factor.

7. The method for operating the hearing device according to claim 6 , wherein, for at least one of said N classes, said deriving of said class weight factor comprises multiplication with an individual class factor and/or addition of an individual class offset.

8. The method for operating the hearing device according to claim 1 , wherein, for at least one of said M sub-functions, a time-averaged activity parameter set is used for adjusting the respective at least one of said M sub-functions.

9. The method for operating the hearing device according to claim 8 , further comprising the step of

choosing an averaging time for said time-averaging in dependence of past changes in the respective activity parameter set.

10. The method for operating the hearing device according to claim 9 , further comprising the steps of

decreasing said averaging time when said past changes in the respective activity parameter set decrease; and

increasing said averaging time when said past changes in the respective activity parameter set increase.

11. The method for operating the hearing device according to claim 1 , wherein at least one of the group comprising beam forming, noise cancelling, feedback cancelling, dynamics processing, filtering is realized by means of at least one of said M sub-functions.

12. A hearing device comprising

an input transducer unit for deriving input audio signals from a current acoustic environment;

an output transducer unit for receiving output audio signals;

a signal processing unit for deriving said output audio signals from said input audio signals by processing said input audio signals according to an adjustable transfer function, which adjustable transfer function describes how said input audio signals relate to said output audio signals and comprises M sub-functions, wherein M is an integer with M≧1;

a classifier unit for deriving, on the basis of said input audio signals and for each class of N classes each of which describes a predetermined acoustic environment, a class similarity factor indicative of the similarity of said current acoustic environment with the predetermined acoustic environment described by the respective class, wherein N is an integer with N≧2;

a base parameter storage unit storing, for each of said M sub-functions, N predetermined base parameter sets each assigned to a different class of said N classes;

a processing unit operationally connected to said base parameter storage unit and adapted to deriving an activity parameter set for each of said M sub-functions, wherein each of said activity parameter sets is derived in dependence of said class similarity factors from the base parameter sets assigned to the respective sub-function;

wherein each of said M sub-functions is adjusted by means of the respective activity parameter set.

13. The hearing device according to claim 12 , with M≧2.

14. The hearing device according to claim 12 , wherein, for each of said N classes, the M base parameter sets assigned to one specific class of said N classes are chosen such that optimized output audio signals are generated when said M base parameter sets are each used for adjusting that sub-function to which the respective base parameter set is assigned and when said current acoustic environment is identical with the predetermined acoustic environment described by said specific class.

15. The hearing device according to claim 12 , wherein each of said activity parameter sets comprises a multitude of values, in particular a multitude of numbers.

16. The hearing device according to claim 12 , wherein each of said activity parameter sets is a single value, in particular, a single number.

17. The hearing device according to claim 12 , wherein said processing unit comprises an averaging unit for deriving, for each of at least one of said M sub-functions, a time-averaged activity parameter set, and wherein said at least one of said M sub-functions is adjusted by means of the respective time-averaged activity parameter set.

18. A hearing device comprising

means for deriving input audio signals from a current acoustic environment;

means for processing said input audio signals according to an adjustable transfer function, which transfer function comprises M sub-functions, wherein M is an integer with M≧1;

means for deriving, on the basis of said input audio signals and for each class of N classes each of which describes a predetermined acoustic environment, a class similarity factor indicative of the similarity of said current acoustic environment with the predetermined acoustic environment described by the respective class, wherein N is an integer with N≧2;

means for deriving an activity parameter set for each of said M sub-functions, wherein each of said activity parameter sets is derived in dependence of said class similarity factors from N base parameter sets assigned to the respective sub-function, wherein each of said N base parameter sets assigned to the respective sub-function is assigned to a different class of said N classes;

wherein each of said M sub-functions is adjusted by means of the respective activity parameter set.

19. A hearing system comprising the hearing device according to one of claims 12 to 18 and, in addition, another device, which is operationally connectable to said hearing device.