Minimum energy tinnitus masker

• US 5,403,262 A
• Filed: 03/09/1993
• Issued: 04/04/1995
• Est. Priority Date: 03/09/1993
• Status: Expired due to Fees

• Current Assignee: Xomed Surgical Products, Inc. (Medtronic Plc)
• Original Assignee: Microtek Medical Incorporated (Ecolab, Inc.)
• Inventors: Gooch, Timothy D.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Lacyk, John P.
• Application Number:
  US08/028,326
• Time in Patent Office: 756 Days
• Field of Search: 600/26-28, 128/746, 607/55
• US Class Current: 600/28
• CPC Class Codes: A61B 5/12 Audiometering
• CPC Class Codes: A61F 11/00 Methods or devices for treatment of the ears or hearing sense implantable prostheses that substitute or replace internal ear parts, e.g. ear-drums, A61F2/18; methods or devices to cause a change in the state of auditory consciousness A61M21/00; electrotherapy applying electrical stimulation of the auditory system, or circuits therefor A61N1/36; radiotherapy using optical stimulation of the auditory system A61N5/06; electro-acoustic hearing aids H04R25/00; Non-electric hearing aids; Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense; Protective devices for the ears, carried on the body or in the hand headwear, e.g. caps or helmets, with means for protecting the ears A42B1/0188, A42B3/16
• CPC Class Codes: H04R 25/75 Electric tinnitus maskers providing an auditory perception

Abstract

A tinnitus masking device and method for producing a masking signal with a selected center frequency, selected bandwidth, and selected volume is provided. A random noise generator and a clock circuit are employed in conjunction with a switched capacitance filter bank to produce a masking signal with the selected center frequency and selected bandwidth. The masking signal is then received by a volume control unit and then amplified for delivery to the tinnitus sufferer'"'"'s ear or ears by speakers or headphones. Additionally, the tinnitus masking device may include a timer and fade out unit.

Claims

1. A tinnitus masking device comprising:

circuit means for producing a masking signal, said masking signal having a selected center frequency and a selected bandwidth;

adjusting means for adjusting the energy level of said masking signal to produce an adjusted masking signal; and

delivering means for delivering said adjusted masking signal to a patient'"'"'s ear; and

wherein said circuit means for producing a masking signal further comprises;

noise generator means for producing a broad band signal,

a circuit clock,

a plurality of filter means for filtering said broad band signal from said noise generator means, each of said filter means cooperating with said circuit clock for selecting said center frequency of said broad band signal, and

means for selecting one of said filter means, such that said masking signal is generated by said selected filter means.

2. A tinnitus masking device comprising:

a circuit means for producing a masking signal, said masking signal having a selected center frequency and a selected bandwidth;

adjusting means for adjusting the energy level of said masking signal to produce an adjusted masking signal; and

delivering means for delivering said adjusted masking signal to a patient'"'"'s ear; and

wherein said circuit means for producing a masking signal further comprises;

means for sampling a predetermined signal, and for producing digitized information corresponding to said predetermined signal, said predetermined signal having a predetermined bandwidth,

means for storing said digitized information,

means for producing a digital signal at a selected rate from said digitized information, and

means for converting said digital signal into said masking signal.

3. A tinnitus masking device comprising:

circuit means for producing a masking signal, said masking signal having a selected center frequency and a selected bandwidth;

adjusting means for adjusting the energy level of said masking signal to produce an adjusted masking signal;

delivering means for delivering said adjusted masking signal to a patient'"'"'s ear; and

wherein said circuit means for producing a masking signal further comprises;

a center frequency selector means for producing an analog center frequency signal corresponding to a selected frequency,

a circuit clock means for receiving said analog center frequency signal,

a digital signal unit cooperating with said circuit clock means for producing a digital center frequency signal at a rate corresponding to said selected center frequency and containing a band of frequencies centered about said center frequency,

a bandwidth selector means for selecting a desired bandwidth and for producing a digital bandwidth signal corresponding to said selected bandwidth,

a digital signal processor means for receiving said bandwidth signal and said digital center frequency signal and for producing a digital masking signal corresponding to said masking signal, and

a digital to analog converter means coupled to said digital signal processor means for generating said masking signal from said digital masking signal.

4. An apparatus for masking tinnitus comprising:

means for producing a broad band signal;

means for centering said broad band signal about a selected frequency;

a plurality of switched capacitance filter means, each of said switched capacitance filter means for filtering said broad band signal to produce a masking signal with a predetermined bandwidth about said predetermined center frequency; and

a selector means for selecting one of said plurality of switched capacitance filter means.

5. The apparatus of claim 4, further comprising an amplifier means for amplifying said masking signal for audio output.

6. The apparatus of claim 4, further comprising an adjustor means for receiving said masking signal and producing an adjusted masking signal therefrom.

7. The apparatus of claim 4 wherein said means for producing said signal further comprises a random noise generator.

8. The apparatus of claim 4 wherein said means for centering said signal about a predetermined frequency comprises:

means for producing a voltage input corresponding to a desired centered frequency;

said means for producing a voltage input for controlling a discharge current of said circuit clock corresponding to said desired center frequency;

a clock circuit; and

said clock circuit in conjunction with said plurality of switched capacitance filter means for centering said signal at a predetermined frequency in response to said voltage input.

9. The apparatus of claim 8, wherein said means for producing said voltage input comprises a potentiometer.

10. An apparatus for masking tinnitus comprising:

means for digitally recording a predetermined masking signal with a predetermined bandwidth;

means for replaying said digitally recorded masking signal as a digital masking signal at a selected rate corresponding to a selected center frequency;

means for converting said digital masking signal into an analog electrical signal; and

means for converting said analog electrical signal into an audio signal.

11. The apparatus of claim 10, wherein said means for converting said analog electrical signal to an audio signal further comprises an energy adjustor control, said energy adjustor control for adjusting the energy level of said audio signal.

12. An apparatus for masking tinnitus comprising:

a center frequency control for selecting a desired center frequency and producing a center frequency signal corresponding to said selected center frequency;

a circuit clock coupled to said center frequency control for receiving said center frequency signal and for producing a circuit time interval in response to said center frequency signal;

a memory bank;

an analog to digital converter coupled to said memory bank for receiving an analog masking signal and converting said analog masking signal into a digital signal and for storing said digital signal in said memory bank;

an address decoder coupled to said circuit clock and said memory bank for developing a digital signal at a rate determined by said circuit time interval and based on said digital signal in said memory bank; and

a digital to analog converter coupled to said decoder and memory bank for converting said digital signal from said decoder and memory bank into an analog masking signal.

13. The apparatus of claim 12, further comprising a means for adjusting the masking signal with respect to the masking signal'"'"'s volume.

14. Apparatus for masking tinnitus comprising:

a center frequency control means for selecting a desired center frequency and to produce a center frequency signal corresponding to said desired center frequency;

a circuit clock means coupled to said center frequency control means for receiving said center frequency signal;

a memory bank for storing digitized information corresponding to an analog broad band masking signal;

an address decoder coupled to said memory bank for, in conjunction with said circuit clock means and said memory bank, producing a digital signal with a specified center frequency;

means for producing a digitized bandwidth signal corresponding to a desired bandwidth;

a digital signal processor means for receiving said digital signal from said decoder and said digital bandwidth signal and to produce therefrom a digital masking signal;

a digital to analog converter means for converting said digital masking signal from said digital signal processor means into an analog masking signal having the desired center frequency and bandwidth; and

a means for adjusting the energy level of said analog masking signal.

15. The apparatus of claim 14, further comprising a housing holding the center frequency control means, circuit clock means, memory bank, address decoder, means for producing a digitized bandwidth signal, digital signal processor, and digital to analog converter means.

16. The apparatus of claim 15, wherein said housing comprises a shell formed to fit over a patient'"'"'s ear.

17. The apparatus of claim 15, wherein said housing comprises a rectangular container formed of a rigid material, said container sized to be portable.

18. The apparatus of claim 15, wherein said housing comprises a shell formed to fit in a patient'"'"'s ear.

19. Apparatus for masking tinnitus comprising:

a pseudo-random noise generator for producing a broad band electrical signal;

a frequency selector switch allowing selection of a selected center frequency;

a circuit clock coupled to said frequency selector switch and for producing a circuit time interval corresponding to said selected frequency;

a plurality of switched capacitance filters, each of said plurality of switched capacitance filters coupled to said pseudo-random noise generator and said circuit clock and in conjunction with said circuit clock and said pseudo-random noise generator producing a masking signal with a selected center frequency and a predetermined bandwidth; and

a bandwidth selector switch coupled to said plurality of switched capacitance filters and for selecting one of said plurality of switched capacitance filters to produce one masking signal.

20. The apparatus of claim 19 and further comprising an amplifier coupled to said bandwidth selector switch for increasing the energy level of said masking signal.

21. The apparatus of claim 19 and further comprising a volume control coupled to said bandwidth selector switch for adjusting the energy level of said masking signal.

22. The apparatus of claim 19 wherein said plurality of switched capacitance filters comprises three switched capacitance filters for producing a one third, one half and one octave bandwidth masking signal.

23. The apparatus of claim 19 further comprising a timing unit coupled to said pseudo-random noise generator for supplying power to said pseudo-random noise generator for a predetermined time period.

24. The apparatus of claim 23 further comprising a fade out unit coupled to said timing unit and said pseudo-random noise generator for gradually decreasing said power to said pseudo-random noise generator over a predetermined time interval when said timing unit terminates the power to said pseudo-random noise generator.

25. A method of masking tinnitus with a masking signal of a selected frequency and selected bandwidth comprising the steps of:

producing broad band signal with a broad band of frequencies;

producing a circuit clock signal;

filtering said broad band signal with a capacitance filter to produce the selected bandwidth;

exciting said capacitance filter with said circuit clock signal to produce the selected center frequency for a masking signal;

adjusting the energy level of said masking signal; and

delivering said masking signal to patient'"'"'s ear.

26. The method of claim 25, wherein the step of producing a broad band signal with a broad band of frequencies comprises electrically exciting a pseudo-random noise generator.

27. The method of claim 25, further comprising the steps of:

selecting a desired time duration for the masking signal; and

limiting the time interval for producing said signal according to said desired time duration with a timing unit.

28. A method for masking tinnitus comprising the steps of:

digitally sampling a predetermined masking signal having a predetermined bandwidth produced by an external device;

storing digital information pertaining to said predetermined masking signal in a memory bank;

retrieving said digital information from said memory bank;

producing a digital masking signal from the memory bank at a predetermined rate corresponding to desired center frequency of an analog masking signal;

converting said digital masking signal to an analog masking signal; and

conditioning said analog masking signal for delivery to patient'"'"'s ear.

29. A method of masking tinnitus comprising the steps of:

selecting a selected center frequency;

producing a digital broad band signal with the selected frequency;

selecting a desired bandwidth;

producing a digital bandwidth signal corresponding to said desired bandwidth;

delivering said digital broad band signal and said digital bandwidth signal to a digital signal processor;

processing said broad band digital signal and said digital bandwidth signal with said digital signal processor to produce a digital masking signal corresponding to an analog masking signal with the desired bandwidth and center frequency;

converting said digital masking signal to an analog masking signal; and

conditioning said analog masking signal for delivery to patient'"'"'s ear.

30. An apparatus for masking a patient'"'"'s tinnitus by developing a masking signal with a minimal amount of energy by using a narrow bandwidth about a selectable center frequency, the apparatus comprising:

clock circuit means for developing a discharge current;

potentiometer means coupled to the clock circuit means for adjusting said discharge current;

a plurality of switched capacitance filters coupled to the clock circuit means and potentiometer means for receiving the discharge current;

noise generating means for producing a broad band electrical noise signal, the noise generating means coupled to the plurality of switched capacitance filters;

each of the plurality of switched capacitance filters receives a portion of the current and the noise signal from the noise generating means and filters the signals to produce a filtered masking signal with a predetermined bandwidth and that corresponds to the discharge current;

a selector coupled to the plurality of switched capacitance filters for selecting one of the plurality of switched capacitance filters and to receive the filtered masking signal therefrom;

a volume unit coupled to the selector attenuating the selected filtered masking signal to a desired level;

means for audio output coupled to the volume unit for receiving the signal therefrom and developing an audio signal for delivery to the patient'"'"'s ear.