Method, medium and apparatus enhancing a bass signal using an auditory property

• US 20080091416A1
• Filed: 06/22/2007
• Published: 04/17/2008
• Est. Priority Date: 10/17/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Kim, Sang-wook, Kim, Jung-ho, Ko, Sang-chul, Kim, Young-tae
• Granted Patent: US 8,386,242 B2
• Time in Patent Office: Days
• US Class Current: 704/200.1
• CPC Class Codes: G10H 1/0091 Means for obtaining special acoustic effects combined with modulation G10H1/043
• CPC Class Codes: G10L 21/02 Speech enhancement, e.g. noise reduction or echo cancellation reducing echo effects in line transmission systems H04B3/20; echo suppression in hands-free telephones H04M9/08
• CPC Class Codes: G10L 21/0264 characterised by the type of parameter measurement, e.g. correlation techniques, zero crossing techniques or predictive techniques
• CPC Class Codes: H04R 2430/03 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04R 3/04 for correcting frequency response

Abstract

Provided are a method, medium and apparatus for enhancing an acoustic signal using an auditory property. An acoustic signal is enhanced by generating a plurality of harmonic signals based on a predetermined acoustic signal frequency, selecting harmonic signals, which exist in an area masked by the predetermined harmonic signal, from among the generated plurality of harmonic signals, and outputting harmonic signals remaining after excluding the selected harmonic signals from the generated plurality of harmonic signals. The enhancement results in a bass signal of good sound quality and having a low distortion ratio, without changing the structure of a micro speaker.

Claims

1. A method of enhancing an acoustic signal, the method comprising:

generating a plurality of harmonic signals based on a predetermined audio signal;

selecting harmonic signals that exist in an area masked by a predetermined harmonic signal, from among the generated plurality of harmonic signals; and

outputting harmonic signals remaining after excluding the selected harmonic signals from the generated plurality of harmonic signals.

2. The method of claim 1, wherein the predetermined harmonic signal is a harmonic signal having a greatest amplitude from among the generated plurality of harmonic signals.

3. The method of claim 1, wherein the predetermined audio signal is generated by filtering a signal having a frequency less than or equal to a minimum reproduction frequency of a speaker outputting the remaining harmonic signals.

4. The method of claim 1, wherein the remaining harmonic signals each have a frequency greater than a minimum reproduction frequency of a speaker outputting the remaining harmonic signals.

5. The method of claim 1, wherein the generating of the plurality of harmonic signals comprises generating the plurality of harmonic signals by modulating amplitudes of the plurality of harmonic signals so that the amplitudes of the plurality of harmonic signals are attenuated proportionally to their harmonic order, with respect to a frequency of the predetermined audio signal.

11. At least one medium comprising computer readable code to control at least one processing element to implement the method of any one of claims 1 through 10.

6. A method of enhancing an acoustic signal, the method comprising:

generating a plurality of harmonic signals based on a predetermined audio signal;

selecting harmonic signals that do not exist in an area masked by a predetermined harmonic signal, from among the generated plurality of harmonic signals;

upon a Total Harmonic Distortion (THD) value, calculated while increasing an order of the selected harmonic signals, exceeding a predetermined THD value, determining a minimum order of harmonic signals, whose THD value exceeds the predetermined THD value, as a limited harmonic order; and

outputting harmonic signals whose order is lower than the determined limited harmonic order from among the selected harmonic signals.

7. The method of claim 6, wherein the predetermined harmonic signal is a harmonic signal having a greatest amplitude from among the generated plurality of harmonic signals.

8. The method of claim 6, wherein the predetermined audio signal is generated by filtering a signal having a frequency less than or equal to a minimum reproduction frequency of a speaker outputting the harmonic signals.

9. The method of claim 6, wherein the harmonic signals each have a frequency greater than a minimum reproduction frequency of a speaker outputting the harmonic signals.

10. The method of claim 6, wherein the generating of the plurality of harmonic signals comprises generating the plurality of harmonic signals by modulating amplitudes of the harmonic signals so that the amplitudes of the harmonic signals are attenuated proportionally to their harmonic order based on the frequency of the predetermined acoustic signal.

12. An apparatus for enhancing a bass signal using an auditory property, the apparatus comprising:

a harmonic generator to generate a plurality of harmonic signals based on a predetermined audio signal;

a harmonic selector to select harmonic signals that are not masked by a predetermined harmonic signal, from among the generated plurality of harmonic signals; and

an output unit to output harmonic signals selected by the harmonic selector.

13. The apparatus of claim 12, wherein the predetermined harmonic signal is a harmonic signal having a greatest amplitude from among the generated plurality of harmonic signals.

14. The apparatus of claim 13, wherein the harmonic selector comprises:

a storage unit to store a masked value per frequency with respect to the harmonic signal having the greatest amplitude from among the generated plurality of harmonic signals;

a comparator to respectively compare amplitudes of the generated plurality of harmonic signals to the masked values stored in the storage unit for each frequency,

wherein as a comparison result of the comparator, harmonic signals, of the plurality of harmonic signals, respectively exceeding masked values stored in the storage unit are selected as harmonic signals that do not exist in an area masked by the predetermined harmonic signal.

15. The apparatus of claim 14, wherein the harmonic selector further comprises a harmonic order determiner, in which if a Total Harmonic Distortion (THD) value calculated while an order of the harmonic signals respectively exceeding masked values stored in the storage unit increases as the comparison result exceeds a predetermined THD value, determines the minimum order of harmonic signals whose THD value exceeds the predetermined THD value as a limited harmonic order,

wherein as the comparison result of the comparator, harmonic signals of an order lower than the order determined by the harmonic order determiner from among harmonic signals respectively exceeding the masked values stored in the storage unit are selected as the harmonic signals non-existing in the area masked by the harmonic signal having the greatest amplitude from among the generated plurality of harmonic signals.

16. The apparatus of claim 12, further comprising a low pass filter (LPF) to perform low pass filtering of an input signal by setting a minimum reproduction frequency of a speaker outputting the harmonic signals as a cutoff frequency,

wherein the harmonic generator generates the plurality of harmonic signals based on a frequency of a predetermined signal filtered by the LPF.

17. The apparatus of claim 12, wherein the harmonic generator generates the plurality of harmonic signals having a frequency greater than the minimum reproduction frequency of the speaker outputting the harmonic signals.

18. The apparatus of claim 12, wherein the harmonic generator generates the plurality of harmonic signals by modulating amplitudes of the harmonic signals so that the amplitudes of the harmonic signals are attenuated proportionally to their harmonic order based on a frequency of a predetermined signal filtered by the LPF.

19. An apparatus for enhancing an acoustic signal, the apparatus comprising:

a harmonic generator to generate a plurality of harmonic signals based on a predetermined audio signal;

a harmonic selector to select harmonic signals masked by a predetermined harmonic signal, from among the generated plurality of harmonic signals; and

an amplitude adjuster to adjust amplitudes of harmonic signals selected by the harmonic selector to “

0.”

20. The apparatus of claim 19, wherein the predetermined harmonic signal is a harmonic signal having a greatest amplitude from among the generated plurality of harmonic signals.

21. The apparatus of claim 20, wherein the harmonic selector comprises:

a storage unit to store a masked value per frequency with respect to the harmonic signal having the greatest amplitude from among the generated harmonic signals;

a comparator to respectively compare generated plurality of harmonic signals to the masked values stored in the storage unit for each frequency,

wherein as a comparison result of the comparator, harmonic signals, of the plurality of harmonic signals, respectively not exceeding masked values stored in the storage unit are selected as harmonic signals existing in an area masked by the predetermined harmonic signal.

22. The apparatus of claim 19, further comprising a low pass filter (LPF) to perform low pass filtering of an input signal by setting a minimum reproduction frequency of a speaker outputting the harmonic signals as a cutoff frequency,

wherein the harmonic generator generates the plurality of harmonic signals based on a frequency of a predetermined signal filtered by the LPF.

23. The apparatus of claim 19, wherein the harmonic generator generates harmonic signals having a frequency greater than the minimum reproduction frequency of the speaker outputting the harmonic signals.

24. The apparatus of claim 19, wherein the harmonic generator generates harmonic signals by modulating amplitudes of the harmonic signals so that the amplitudes of the harmonic signals are attenuated proportionally to their harmonic order based on a frequency of a predetermined signal filtered by the LPF.

25. The apparatus of claim 19, further comprising an output unit to output the plurality of harmonic signals generated by the harmonic generator.

26. A method of representing an audio signal using a plurality of harmonics generated from the audio signal, the method comprising:

generating a masking curve based on a harmonic of the audio signal; and

selecting only unmasked harmonics, based on the generated masking curve, to represent the audio signal.

27. The method of claim 26, wherein the harmonic is predetermined as a harmonic having a greatest amplitude from among the generated plurality of harmonics.

28. The method of claim 26, wherein the audio signal is predetermined and is generated by filtering a signal having a frequency lower than a minimum reproduction frequency of a speaker outputting the remaining harmonic signals.

29. The method of claim 26, wherein the selected harmonics each have a frequency greater than a minimum reproduction frequency of a speaker outputting the selected harmonics.

30. At least one medium comprising computer readable code to control at least one processing element to implement the method of claim 26.