AUTOMATIC GAIN CONTROL FOR IMPLANTED MICROPHONE

• US 20090187065A1
• Filed: 01/21/2009
• Published: 07/23/2009
• Est. Priority Date: 01/21/2008
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Otologics, LLC (Cochlear Limited)
• Inventors: BASINGER, DAVID L.
• Granted Patent: US 8,641,595 B2
• Time in Patent Office: Days
• US Class Current: 600/25
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: G10L 25/84 for discriminating voice from noise
• CPC Class Codes: H03G 3/301 the gain being continuously variable
• CPC Class Codes: H04R 2225/67 Implantable hearing aids or parts thereof not covered by H04R25/606
• CPC Class Codes: H04R 25/356 Amplitude, e.g. amplitude shift or compression
• CPC Class Codes: H04R 25/505 using digital signal processing
• CPC Class Codes: H04R 25/606 acting directly on the eardrum, the ossicles or the skull, e.g. mastoid, tooth, maxillary or mandibular bone, or mechanically stimulating the cochlea, e.g. at the oval window
• CPC Class Codes: H04R 3/04 for correcting frequency response

Abstract

An implantable hearing instrument is provided that reduces the response to unnaturally high vibrations (e.g., due to a patient'"'"'s own voice), without necessarily or substantially affecting the response to desired signals. The implantable hearing instrument system is operative to selectively alter/lower the gain of signals that have a magnitude above a predetermined threshold. Signals having unnaturally large amplitudes (e.g., due to a patient'"'"'s own voice) are amplified less than desired signals, so that a patient may experience a more representative sound.

Claims

1. An implantable hearing system, comprising:

an implantable microphone operative to generate microphone output responses;

an amplifier operative to receive said microphone output responses and generate amplifier output responses, wherein said amplifier output responses are dependent upon a characteristic of said microphone output responses;

a signal processor operative to receive said amplifier output responses and further operative to process said amplifier output responses and generate signal processor output responses; and

an implantable auditory stimulation device operative to stimulate an auditory component of a patient in accordance with said signal processor output responses.

2. The implantable hearing system of claim 1, wherein said amplifier comprises:

an AGC circuit.

3. The implantable hearing system of claim 2, wherein said characteristic of said microphone output responses includes an amplitude characteristic.

4. The implantable hearing system of claim 3, wherein said AGC circuit is operative to selectively lower the gain for amplifying microphone output responses having a magnitude above a predetermined threshold.

5. The implantable hearing system of claim 3, wherein said AGC circuit is operative to amplify microphone output responses by a first value when said microphone output responses are below a threshold, and to amplify said microphone output responses by a second value less than said first value when said microphone output responses are above said threshold.

6. The implantable hearing system of claim 3, wherein an amplification level for said AGC circuit is a nonlinear function of the amplitude of said microphone output responses.

7. The implantable hearing system of claim 1, wherein said characteristic of said microphone output responses is a frequency characteristic.

8. The implantable hearing system of claim 7, wherein said amplifier is operative to amplify microphone output responses in a first frequency band by a first factor, and to amplify microphone output responses in a second frequency band by a second factor which is greater than said first factor.

9. The implantable hearing system of claim 8, wherein said first frequency band is predetermined dependent upon a characteristic of the voice of a patient.

11. The implantable hearing system of claim 1, wherein said microphone includes a first dynamic range and said signal processor includes a second dynamic range less than said first dynamic range, and wherein said amplifier is operative to compress said first dynamic range to substantially fit said second dynamic range.

12. The implantable hearing system of claim 1, wherein said amplifier is operative to provide a gain indicator signal to said signal processor, and wherein said signal processor is operative to process said amplifier output responses dependent upon said gain indicator signal.

13. A method for use in an implantable hearing instrument, comprising:

receiving an output signal from an implanted microphone;

identifying a first characteristic of said output signal;

based on said first characteristic, amplifying said microphone output signal by at least one of a plurality of gain settings to produce an amplified signal, wherein said plurality of gain setting comprise at least two different gain settings;

inputting said amplified signal into a signal processor;

processing said amplified signal to generate a transducer drive signal; and

using said transducer drive signal to actuate an implantable auditory stimulation device operative to stimulate an auditory component.

14. The method of claim 13, wherein identifying said first characteristic comprises:

identifying a magnitude of said output signal.

15. The method of claim 14, further comprising:

identifying a magnitude of a predetermined frequency range of said output signal.

16. The method of claim 13, wherein amplifying comprises:

utilizing a non-linear function to amplify said microphone output signal.

17. The method of claim 13, wherein amplifying comprises:

amplifying a first frequency portion of said microphone output signal associated with a voice of a user using a first gain setting and amplifying at least a second frequency portion of said microphone output signal with a second gain setting, where said second gain setting is larger than said first gain setting.

18. The method of claim 13, wherein amplifying comprises compressing an output range of said microphone output signal.

19. A method for use in an implantable hearing instrument, comprising:

receiving an microphone output signal from an implanted microphone;

receiving an output signal from an accelerometer;

upon identifying a identifying a first characteristic of interest in said accelerometer adjusting a gain setting;

amplifying said microphone output signal using said gain setting to produce an amplified signal;

processing said amplified signal to generate a transducer drive signal; and

using said transducer drive signal to actuate an implantable auditory stimulation device operative to stimulate an auditory component.

20. The method of claim 19, wherein identifying a first characteristic comprises:

comparing said output signal of said accelerometer to said microphone output signal.

21. The method of claim 19, wherein identifying a first characteristic comprises:

monitoring a predetermined frequency band of said output signal of said accelerometer.

22. The method of claim 21, wherein said predetermined frequency band comprises a frequency band associated with a voice of a user of the hearing instrument.

23. A method for use in an implantable hearing instrument, comprising:

receiving an microphone output signal from an implanted microphone;

identifying an own voice event;

amplifying the microphone output signal in a first frequency band by a first factor;

amplifying the microphone output signal in a second frequency band by a second factor which is greater than said first factor, wherein amplifying generates a non-linearly amplified signal;

processing said amplified signal to generate a transducer drive signal; and

using said transducer drive signal to actuate an implantable auditory stimulation device operative to stimulate an auditory component.

24. The method of claim 23, wherein identifying an own voice event comprises:

monitoring an accelerometer output signal to identify a non-ambient signal having at least a predetermined magnitude.