Hearing aids providing protection against sudden loud sounds

1. A hearing aid comprising:

a microphone; and

a processing unit;

wherein the microphone is configured to receive sound incident on the hearing aid and deliver a corresponding microphone output to the processing unit; and

wherein the processing unit is configured to process the microphone output to determine whether the incident sound comprises potentially harmful impulsive sound, and to generate a processor output comprising a processed version of the microphone output.

2. The hearing aid of claim 1 , wherein the determination is based in part on whether the incident sound received by the microphone comprises a portion characterized by a noise waveform meeting a predetermined criterion.

3. The hearing aid of claim 2 , wherein the predetermined criterion comprises exceeding a first threshold loudness level.

4. The hearing aid of claim 3 , wherein the first threshold loudness level is 120 dBA.

5. The hearing aid of claim 2 , wherein the predetermined criterion comprises exceeding a first threshold rise rate beginning at a loudness level equal to a second threshold loudness level.

6. The hearing aid of claim 5 , wherein the first threshold rise rate is 5 dBA per second and the second threshold loudness level is 80 dBA.

7. The hearing aid of claim 2 , additionally comprising one or more controllable vents, configured to be closed automatically in response to a determination from the processing unit that the incident sound received by the microphone comprises potentially harmful impulsive sound.

8. The hearing aid of claim 1 , wherein the processing unit comprises active noise cancellation (ANC) circuitry, the ANC circuitry being activated automatically in response to a determination that the incident sound received by the microphone comprises potentially harmful impulsive sound, and operable to generate an anti-noise waveform that is included in the processor output.

9. The hearing aid of claim 1 , additionally comprising an earpiece comprising a speaker,

wherein a housing containing the microphone and the processing unit is configured to be worn either behind, or tucked into a fold of, a pinna of an ear of a user;

wherein the earpiece is configured to be positioned within or at an entrance of the ear canal of the ear; and

wherein an audible output generated by the speaker is delivered from the earpiece directly into the ear canal of the user.

10. A method of providing protection to a wearer of a hearing aid from sudden loud sounds; the method comprising:

using a microphone in the hearing aid to receive incident sound and deliver a corresponding microphone output to a processing unit in the hearing aid; and

using the processing unit to process the microphone output to generate a first processor output, determined by whether the incident sound comprises potentially harmful impulsive sound, and to generate a second processor output comprising a processed version of the microphone output.

11. The method of claim 10 , wherein the determination is based in part on whether the incident sound received by the microphone comprises a portion characterized by a noise waveform meeting a predetermined criterion.

12. The method of claim 11 , wherein the predetermined criterion comprises exceeding a first threshold loudness level.

13. The method of claim 12 , wherein the first threshold loudness level is 120 dBA.

14. The method of claim 11 , wherein the predetermined criterion comprises exceeding a first threshold rise rate beginning at a loudness level equal to a second threshold loudness level.

15. The method of claim 14 , wherein the first threshold rise rate is 5 dBA per second and the second threshold loudness level is 80 dBA.

16. The method of claim 10 , wherein the processing comprises automatically activating active noise cancellation (ANC) circuitry in the processing unit in response to a determination that the incident sound received by the microphone comprises potentially harmful impulsive sound, the ANC circuitry operating to generate a corresponding anti-noise waveform.

17. The method of claim 16 , additionally comprising using a speaker in an earpiece of the hearing aid to generate an audible output corresponding to the second processor output;

wherein the second processor output comprises a combination of a signal corresponding to the noise waveform and a signal corresponding to the anti-noise waveform, such that the audible output generated by the speaker and potentially heard by a wearer of the hearing aid is substantially free of sound corresponding to the portion of incident sound characterized by the noise waveform.

18. The method of claim 17 ,

wherein a housing containing the microphone and the processing unit is worn either behind, or tucked into a fold of, a pinna of an ear of a user;

wherein the earpiece is positioned within or at an entrance of the ear canal of the ear; and

wherein the audible output generated by the speaker is delivered from the earpiece directly into the ear canal of the user.

19. The method of claim 11 , additionally comprising automatically closing one or more controllable vents in response to a determination that the incident sound received by the microphone comprises potentially harmful impulsive sound.