Claims
- 1. A method for improving clarity of an input signal for a hearing aid, the method comprising:selecting frequencies of the input signal for processing; and adding even harmonic distortion to the selected frequencies by applying a nonlinear transfer function having a ratio of positive half-cycle gain to a negative half-cycle gain greater than unity.
- 2. The method of claim 1 wherein:the even harmonic distortion added to the selected frequencies is of at least the second order.
- 3. The method of claim 1 wherein adding comprises:applying a nonlinear transfer function having a unity gain for positive half-cycles and a gain less than unity for negative half-cycles.
- 4. The method of claim 3 wherein:the nonlinear transfer function has a variable negative half cycle gain.
- 5. The method of claim 1 wherein selecting comprises:attenuating a portion of the frequencies of the input signal by applying a gain less than unity so as to deselect that portion.
- 6. The method of claim 1 wherein selecting comprises:amplifying a portion of the frequencies of the input signal by applying a gain greater than unity so as to select that portion.
- 7. A method for improving clarity of an audio signal for a phone switch, the method comprising:selecting frequencies of the audio signal for processing; and adding even harmonic distortion to the selected frequencies by applying a nonlinear transfer function having a ratio of positive half-cycle gain to negative half-cycle gain greater than unity.
- 8. The method of claim 7 wherein:the even harmonic distortion added to the selected frequencies is of at least the second order.
- 9. The method of claim 7 wherein:the phone switch is a central office telephone switch.
- 10. The method of claim 7 wherein:the phone switch is a cellular phone switch.
- 11. The method of claim 7 wherein adding comprises:applying a nonlinear transfer function having a unity gain for positive half-cycles and a gain less than unity for negative half-cycles.
- 12. The method of claim 11 wherein:the nonlinear transfer function has a variable negative half cycle gain.
- 13. A method of improving clarity of an audio signal for a voice messaging system, the method comprising:selecting frequencies of the audio signal for processing; and adding even harmonic distortion to the selected frequencies by applying a nonlinear transfer function having a ratio of positive half-cycle gain to negative half-cycle gain greater than unity.
- 14. The method of claim 13 wherein:the even harmonic distortion added to the selected frequencies is of at least the second order.
- 15. The method of claim 13 wherein adding comprises:applying a nonlinear transfer function having a unity gain for positive half-cycles and a gain less than unity for negative half-cycles.
- 16. The method of claim 15 wherein:the nonlinear transfer function has a variable negative half cycle gain.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 08/587,126, filed Jan. 11, 1996, now U.S. Pat. No. 6,023,513.
US Referenced Citations (11)
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
08/587126 |
Jan 1996 |
US |
Child |
08/956677 |
|
US |