Method of compensating audio frequency response characteristics in real-time and a sound system using the same

• US 20060140418A1
• Filed: 08/30/2005
• Published: 06/29/2006
• Est. Priority Date: 12/28/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Koh, You-kyung, Kim, Sun-min, Lee, Joon-hyun
• Granted Patent: US 8,059,833 B2
• Time in Patent Office: Days
• US Class Current: 381/98
• CPC Class Codes: H04R 25/70 Adaptation of deaf aid to hearing loss, e.g. initial electronic fitting

Abstract

A method of compensating audio frequency response characteristics of a portable sound system can be performed using acoustic characteristics of a user measured in real-time. The method of compensating the audio frequency response characteristics can be used by a portable sound system. The method includes generating an acoustic characteristics curve of a user based on a minimum perception level of a user with respect to audible audio frequency bandwidths, generating an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve, and compensating the audio frequency response characteristics of a sound based on the acoustic compensation curve of the user.

Claims

1. A method of compensating audio frequency response characteristics of a sound system in real-time, the method comprising:

generating an acoustic characteristics curve of a user based on a minimum perception level of the user with respect to audible audio frequency bandwidths;

generating an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve; and

compensating the audio frequency response characteristics of a sound based on the acoustic compensation curve of the user.

2. The method of claim 1, wherein the generating of the acoustic compensation curve of the user comprises:

dividing the audible frequency bandwidths into a plurality of bands;

reproducing an audio signal in each of the bands;

setting an acoustic level of the user for each of the bands when the user first hears a sound of the audio signal through an earphone while controlling a volume of the audio signal in each of the bands; and

generating the acoustic characteristics curve of the user based on the acoustic level of the user in each of the bands.

3. The method of claim 1, wherein the generating of the acoustic compensation curve of the user comprises:

dividing the acoustic characteristics curve of the user into bands of a predetermined width and setting a representative sound pressure level for each of the bands;

calculating a difference between the set representative sound pressure level of each of the bands and a predetermined reference level; and

setting filter coefficients to reflect the calculated difference between the set representative sound pressure level of each of the bands and the predetermined reference level.

4. The method of claim 1, further comprising:

selectively applying a predetermined equalizer and a sound effect unit to the acoustic characteristics curve reflecting filter coefficients determined from the acoustic compensation curve of the user.

5. The method of claim 1, wherein the predetermined frequency characteristics target curve comprises a frequency response characteristics curve desired by the user.

6. The method of claim 1, wherein the predetermined frequency characteristics target curve comprises a frequency response characteristics curve of a best quality earphone.

7. A method of reproducing sound in a sound system, the method comprising:

detecting acoustic characteristics of a user; and

reproducing a sound signal and modifying a frequency response curve of the sound signal according to the detected acoustic characteristics of the user.

8. The method of claim 7, wherein the detecting of the acoustic characteristics of the user comprises receiving a plurality of inputs from the user according to a plurality of sounds heard by the user in a plurality of audible frequency bands.

9. The method of claim 7, wherein the detecting of the acoustic characteristics of the user comprises:

determining a minimum perception level of sound for the user with respect to a plurality of audible frequency bands;

generating an acoustic characteristic curve for the user according to the minimum perception levels; and

determining a compensation curve that makes the acoustic characteristic curve of the user a target frequency response curve.

10. The method of claim 9, wherein the modifying of the frequency response of the sound signal comprises applying the compensation curve to the sound signal to change the frequency response curve of the sound signal to the target frequency response curve.

11. The method of claim 7, wherein:

the detecting of the acoustic characteristics of the user comprises determining a user characteristics curve; and

the modifying of the frequency response curve of the sound signal comprises generating filter coefficients according to the determined user characteristics curve and filtering the frequency response curve of the sound signal according to the generated filter coefficients.

12. The method of claim 7, wherein the modifying of the frequency response curve of the sound signal comprises:

generating a first equalizer that is specific to the detected acoustic characteristics of the user; and

equalizing the frequency response curve of the sound signal by applying the first equalizer thereto.

13. The method of claim 12, wherein the modifying of the frequency response curve of the sound signal further comprises:

applying a second equalizer having one or more preset equalization modes to the equalized frequency response curve of the sound signal; and

applying a virtualizer to the equalized frequency response curve of the sound signal to add one or more sound effects to the equalized sound signal.

14. The method of claim 7, wherein:

the detecting of the acoustic characteristics of the user comprises determining an equal loudness curve at a plurality of audible frequencies; and

the modifying of the frequency response curve of the sound signal comprises flattening the frequency response curve of the sound signal using the determined equal loudness curve.

15. The method of claim 7, wherein:

the detecting of the acoustic characteristics of the user comprises generating an audiogram of a hearing ability of the user according to one or more user inputs; and

the modifying of the frequency response curve of the sound signal comprises equalizing a plurality of frequency components of the frequency response curve of the sound signal according to the generated audiogram.

16. The method of claim 7, wherein:

the detecting of the acoustic characteristics of the user comprises;

generating an audiogram in a frequency domain,

dividing the audiogram into octave bands each having a representative sound pressure level,

determining differences between each of the representative sound pressure levels and a reference sound pressure level, and

generating one or more infinite impulse response (IIR) coefficients to reflect the differences between the representative sound pressure levels and the reference sound pressure level; and

the modifying of the frequency response curve of the sound signal comprises applying the one or more IIR coefficients to a filter to filter the frequency response curve of the sound signal.

17. A sound system, comprising:

a sound reproducing unit to reproduce a sound from a predetermined recording medium;

an acoustic characteristics processing unit to generate an acoustic characteristics curve of a user based on a minimum perception level of the user with respect to an audible audio frequency band;

an equalizer to generate filter coefficients that correspond to an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve; and

a digital filter processing unit to compensate frequency response characteristics of the sound that is reproduced by the sound reproducing unit according to the filter coefficients generated by the equalizer.

18. The sound system of claim 17, wherein the acoustic characteristics processing unit comprises:

a signal output unit to output audio signals for each of a plurality of bands within the audible frequency band;

a volume controller to control a volume of the audio signal that corresponds to one of the bands output by the signal output unit;

a display unit to display information to determine whether the volume controlled audio signal is audible by the user;

a user input unit to output a signal when the user presses a button to indicate that a sound of the volume controlled audio signal is audible when the user hears the sound through an earphone; and

an acoustic level setting unit to set an acoustic level of the user for each of the bands in the audible frequency band when the button is pressed at the user input unit and to generate an acoustic characteristics curve of the user by applying the acoustic levels of the user to a filter.

19. The sound system of claim 17, wherein the digital filter processing unit comprises an acoustic compensation filter, a predetermined equalizer, and a predetermined sound effect unit that are arranged together.

20. A sound system, comprising:

a user acoustics unit to detect acoustic characteristics of a user;

a sound reproducing unit to reproduce a sound signal; and

a processing unit to modify a frequency response curve of the reproduced sound signal according to the detected acoustic characteristics of the user.

21. The system of claim 20, wherein the user acoustics unit detects the acoustic characteristics of the user by receiving a plurality of inputs from the user according to a plurality of sounds heard by the user in a plurality of audible frequency bands.

22. The system of claim 20, wherein the user acoustics unit comprises an acoustics curve generating unit to determine a minimum perception level of sound for the user with respect to a plurality of audible frequency bands, to generate an acoustic characteristics curve for the user according to the minimum perception levels, and to determine a compensation curve that makes the acoustic characteristics curve of the user a target frequency response curve.

23. The system of claim 22, wherein the processing unit modifies the frequency response of the sound signal by applying the compensation curve to the sound signal to change the frequency response curve of the sound signal to the target frequency response curve.

24. The system of claim 20, wherein the user acoustics unit comprises:

an acoustics curve generating unit to determine a user characteristics curve, and

an equalizer generating unit to generate filter coefficients according to the determined user characteristics curve; and

the processing unit comprises filter to filter the frequency response curve of the sound signal of the sound signal according to the generated filter coefficients.

25. The system of claim 20, wherein the processing unit comprises:

a first equalizer that is specific to the detected acoustic characteristics of the user to equalize the frequency response curve of the sound signal.

26. The system of claim 25, wherein the processing unit further comprises:

a second equalizer having one or more preset equalization modes to re-equalize the equalized frequency response curve of the sound signal; and

a virtualizer to add one or more sound effects to the re-equalized frequency response curve of the sound signal.

27. The system of claim 20, wherein the user acoustics unit detects the acoustic characteristics of the user by determining an equal loudness curve at a plurality of audible frequencies, and the processing unit flattens the frequency response curve of the reproduced sound signal using the determined equal loudness curve.

28. The system of claim 20, wherein the user acoustics unit comprises:

a curve generating unit to generate an audiogram of a hearing ability of the user according to one or more user inputs; and

an equalizer generating unit to generate an equalizer to equalize a plurality of frequency components of the frequency response curve of the reproduced sound signal according to the generated audiogram.

29. The system of claim 20, wherein the user acoustics unit generates an audiogram in a frequency domain, divides the audiogram into octave bands each having a representative sound pressure level, determines differences between each of the representative sound pressure levels and a reference sound pressure level, and generates one or more infinite impulse response (IIR) coefficients to reflect the differences between the representative sound pressure levels and the reference sound pressure level, and the processing unit comprises a filter to filter the frequency response curve of the sound signal according to the one or more IIR coefficients.

30. The system of claim 20, further comprising:

an input unit to receive one or more inputs from the user to indicate when the user hears a plurality of sounds such that the user acoustics unit detects the acoustic characteristics of the user accordingly.

31. The system of claim 30, further comprising:

a display unit to instruct the user to select a specified input whenever the user first hears a sound.

33. The system of claim 30, further comprising:

a selection unit to enable a user to select between the reproducing mode and the measuring mode.

34. The system of claim 30, wherein the generated sound processing unit comprises:

a first equalizer to transform the reproduced sound signal to have a target frequency response by compensating for a frequency response of the user-specific acoustics; and

at least one of a second equalizer having one or more preset equalization modes and a sound effect unit.

32. A sound system, comprising:

a sound reproducing unit to reproduce a sound signal when the system is in a sound reproducing mode; and

an acoustics measuring unit to generate a user-specific sound processing unit to process sound according user-specific acoustics and one or more user preferences in real time when the system is in a measuring mode.

35. A method of compensating audio frequency response characteristics, the method comprising:

generating an acoustic characteristics curve by checking levels of each of a plurality of bands in a frequency domain;

dividing the acoustic characteristics curve into curve bands of a predetermined width and setting a representative sound pressure level for each of the curve bands;

calculating a difference between the representative sound pressure level of each of the curve bands and preset reference levels; and

setting filter coefficients according to the calculated difference between the representative sound level of each of the curve bands and the preset reference levels.

36. A computer readable medium containing executable code to compensate audio frequency response characteristics of a sound system in real-time, the medium comprising:

a first executable code to generate an acoustic characteristics curve of a user based on a minimum perception level of the user with respect to audible audio frequency bandwidths;

a second executable code to generate an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve; and

a third executable code to compensate the audio frequency response characteristics of a sound based on the acoustic compensation curve of the user.