Customizing audio output to a user's hearing in a digital telephone

• US 6,212,496 B1
• Filed: 10/13/1998
• Issued: 04/03/2001
• Est. Priority Date: 10/13/1998
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Robertson, Daniel, Campbell, Lowell
• Primary Examiner(s): Hudspeth, David R.
• Assistant Examiner(s): Wieland, Susan
• Application Number:
  US09/170,988
• Time in Patent Office: 903 Days
• Field of Search: 704/221, 704/222, 704/271, 381/56, 381/103, 381/66, 381/23.1, 381/303, 381/312, 379/406, 379/411, 379/457
• US Class Current: 704/221
• CPC Class Codes: G10L 2021/065 Aids for the handicapped in understanding
• CPC Class Codes: G10L 21/00 Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility G10L19/00 takes precedence
• CPC Class Codes: H04R 25/505 using digital signal processing

Abstract

Methods and apparatus implementing a technique for producing an audio output customized to a listener'"'"'s hearing impairment through a digital telephone. A user initially sets user parameters to represent the user'"'"'s hearing spectrum. In receiving a call, the digital telephone receives an input signal. The digital telephone adjusts the input signal according to the user parameters and generates an output signal based upon the adjusted input signal.

Claims

1. A method of adjusting audio output of a digital telephone, comprising:

obtaining user parameters which represent a user'"'"'s individual hearing spectrum, wherein obtaining the user parameters comprises

generating a plurality of tones with the digital telephone,

receiving a user response to a plurality of said tones entered into the digital telephone, and

setting a user parameter based upon the user responses;

receiving a digital input signal representing information to be heard by the user;

adjusting the digital input signal according to the user parameters to form a hearing-adjusted digital signal; and

generating an analog output signal based upon the hearing-adjusted digital signal.

2. The method of claim 1, wherein setting the user parameters comprises:

repeatedly generating a test tone at a frequency with varying amplitude according to user responses until a hearing threshold is determined for the frequency; and

setting a user parameter based upon the hearing threshold.

3. The method of claim 1, wherein the user parameters divide an audio spectrum into a plurality of bands and indicate the user'"'"'s ability to hear for each band.

4. The method of claim 3, wherein adjusting the digital input signal comprises:

amplifying the digital input signal in frequency bands in which the user parameters indicate the user'"'"'s hearing is impaired.

5. The method of claim 3, wherein adjusting the digital input signal comprises:

digitally shifting the pitch lag parameter of the digital input signal from frequency bands in which the user parameters indicate the user'"'"'s hearing is impaired to frequency bands in which the user parameters indicate the user'"'"'s hearing is less impaired.

6. The method of claim 5, further comprising:

using a vocoder to process the digital input signal,

wherein the shifting of the digital input signal comprises shifting poles and zeroes of a vocal tract filter function in the vocoder.

7. A method of adjusting audio output of a digital telephone, comprising:

obtaining user parameters which represent a user'"'"'s individual hearing spectrum, wherein obtaining the user parameters comprises

generating a plurality of tones with the digital telephone,

receiving a user response to a plurality of said tones entered into the digital telephone, and

setting a user parameter based upon the user responses;

receiving a digital signal;

decoding the received digital signal using a vocoder;

using the vocoder to shift the pitch lag parameter of the decoded digital signal from frequency bands in which the user parameters indicate the user cannot hear to frequency bands in which the user parameters indicate the user can hear, in addition to using the vocoder to shift the poles and zeros of the vocal tract filter function in the vocoder, forming a shifted digital signal; and

generating an analog output signal based upon the digital signal.

8. The method of claim 7, further comprising:

applying a fast Fourier transform to the shifted digital signal to convert the shifted digital signal from a time domain into a frequency domain;

amplifying the converted digital signal in frequency bands in which the user parameters indicate the user'"'"'s hearing is impaired; and

applying an inverse fast Fourier transform to the amplified digital signal to convert the amplified digital signal from the frequency domain into the time domain.

9. A method of adjusting audio output of a digital telephone, comprising:

obtaining user parameters which represent a user'"'"'s individual hearing spectrum, wherein obtaining the user parameters comprises

generating a plurality of tones with the digital telephone,

receiving a user response to a plurality of said tones entered into the digital telephone, and

setting a user parameter based upon the user responses;

receiving a digital signal;

decoding the received digital signal using a vocoder;

applying a fast Fourier transform to the digital signal to convert the digital signal from a time domain into a frequency domain;

amplifying the converted digital signal in frequency bands in which the user parameters indicate the user'"'"'s hearing is impaired;

applying an inverse fast Fourier transform to the amplified digital signal to convert the amplified digital signal from the frequency domain into the time domain; and

generating an analog output signal based upon the digital signal.

10. The method of claim 9, further comprising:

using the vocoder to shift the digital signal from frequency bands in which the user parameters indicate the user cannot hear to frequency bands in which the user parameters indicate the user can hear by shifting poles and zeroes of a filter function in the vocoder.

11. A method of adjusting audio output of a digital telephone to match a user'"'"'s individual hearing ability, comprising:

first, adjusting a received digital signal according to a first set of user parameters which represent a first user'"'"'s hearing ability; and

second, adjusting a received digital signal according to a second set of user parameters which represent a second user'"'"'s hearing ability.

12. A digital telephone for adjusting audio output to a user'"'"'s individual hearing spectrum, comprising:

an audio output;

an audio input;

an entry for receiving a digital signal;

a case coupled to the audio output, the audio input, and the entry;

a memory for storing user parameters which represent the user'"'"'s individual hearing ability; and

a digital signal processor coupled to the memory, the entry, and the audio output, wherein the digital signal processor includes a vocoder connected to the entry and a frequency transformation element, and

wherein the digital signal processor shifts the signal from frequency bands in which the user parameters stored in the memory indicate the user'"'"'s hearing is impaired to frequency bands in which the user parameters indicate the user'"'"'s hearing is not impaired, and

wherein the digital signal processor amplifies the shifted signal in frequency bands in which the user parameters stored in the memory indicate the user'"'"'s hearing is impaired.

13. The digital telephone of claim 12, wherein adjusting the digital signal comprises:

amplifying the digital signal in frequency bands in which the user parameters indicate the user'"'"'s hearing is impaired.

14. The digital telephone of claim 12, wherein adjusting the digital signal comprises:

shifting the digital signal from frequency bands in which the user parameters indicate the user'"'"'s hearing is impaired to frequency bands in which the user parameters indicate the user'"'"'s hearing is less impaired.

15. A digital telephone for adjusting a digital signal according to a user'"'"'s hearing ability, comprising:

a user parameter control element including a memory for storing user parameters representing the user'"'"'s hearing ability;

a receiving element for receiving a signal;

a digital signal processor connected to the user parameter control element and the receiving element, where the digital signal processor includes a vocoder connected to the receiving element and a frequency transformation element, and

where the digital signal processor shifts the signal from frequency bands in which the user parameters stored in the memory indicate the user'"'"'s hearing is impaired to frequency bands in which the user parameters indicate the user'"'"'s hearing is not impaired, and

where the digital signal processor amplifies the shifted signal in frequency bands in which the user parameters stored in the memory indicate the user'"'"'s hearing is impaired; and

an output element connected to the digital signal processor, for outputting the amplified signal.

16. The digital telephone of claim 15, where the frequency transformation element includes at least one amplifier.

17. The digital telephone of claim 15, where the vocoder shifts the signal.

18. The digital telephone of claim 15, where the frequency transformation element amplifies the shifted signal.

19. The digital telephone of claim 15, where the vocoder includes a long-term codebook and a short-term codebook.