1. A method for post-processing a decoded sound signal in view of enhancing a perceived quality of said decoded sound signal, comprising: dividing the decoded sound signal into a plurality of frequency sub- band signals; and applying post-processing to at least one of the frequency sub-band signals, but not all the frequency sub-band signals.

2. A post-processing method as defined in claim 1 , further comprising summing the frequency sub-band signals, after post-processing of said at least one frequency sub-band signal, to produce an output post-processed decoded sound signal.

3. A post-processing method as defined in claim 1 , wherein applying post-processing to at least one of the frequency sub-band signals comprises adaptively filtering said at least one frequency sub-band signal.

4. A post-processing method as defined in claim 1 , wherein dividing the decoded sound signal into a plurality of frequency sub-band signals comprises sub-band filtering the decoded sound signal to produce the plurality of frequency sub-band signals.

5. A post-processing method as defined in claim 1 , wherein, for said at least one of the frequency sub-band signals: applying post-processing comprises adaptively filtering the decoded sound signal; and dividing the decoded sound signal comprises sub-band filtering the adaptively filtered decoded sound signal.

6. A post-processing method as defined in claim 1, wherein: dividing the decoded sound signal into a plurality of frequency sub- band signals comprises:', '- high-pass filtering the decoded sound signal to produce a frequency high- band signal; and', '- low-pass filtering the decoded sound signal to produce a frequency low- band signal; and applying post-processing to at least one of the frequency sub-band signals comprises: - applying post-processing to the decoded sound signal prior to low-pass filtering the decoded sound signal to produce the frequency low-band signal.

7. A post-processing method as defined in claim 6, wherein applying post-processing to the decoded sound signal comprises pitch enhancing said decoded sound signal to reduce an inter-harmonic noise in the decoded sound signal.

8. A post-processing method as defined in claim 7, further comprising low-pass filtering the decoded sound signal prior to pitch enhancing said decoded sound signal.

9. A post-processing method as defined in claim 6, further comprising summing the frequency high-band and low-band signals to produce an output post-processed decoded sound signal

10. A post-processing method as defined in claim 1, wherein: dividing the decoded sound signal into a plurality of frequency sub- band signals comprises: - band-pass filtering the decoded sound signal to produce a frequency upper-band signal; and - low-pass filtering the decoded sound signal to produce a frequency lower- band signal; and applying post-processing to at least one of the frequency sub-band signals comprises: - applying post-processing to the frequency lower-band signal

11. A post-processing method as defined in claim 10, wherein applying post-processing to the frequency lower-band signal comprises pitch enhancing said frequency lower-band signal prior to low-pass filtering the decoded sound signal

12. A post-processing method as defined in claim 10, further comprising summing the frequency upper-band and lower-band signals to produce an output post-processed decoded sound signal

13. A post-processing method as defined in claim 1 , wherein: dividing the decoded sound signal into a plurality of frequency sub- band signals comprises:', '- low-pass filtering the decoded sound signal to produce a frequency low- band signal; and applying post-processing to at least one of the frequency sub-band signals comprises:', '- applying post-processing to the frequency low-band signal

14. A post-processing method as defined in claim 13, wherein applying post-processing to the frequency low-band signal comprises processing the decoded sound signal through an inter-harmonic filter for inter-harmonic attenuation of the decoded sound signal

15. A post-processing method as defined in claim 14, wherein applying post-processing to the frequency low-band signal comprises multiplying the inter-harmonic filtered decoded sound signal by an adaptive pitch enhancement gain

16. A post-processing method as defined in claim 14, further comprising low-pass filtering the decoded sound signal prior to processing the decoded sound signal through the inter-harmonic filter

17. A post-processing method as defined in claim 13, further comprising summing the decoded sound signal and the frequency low-band signal to produce an output post-processed decoded sound signal

18. A post-processing method as defined in claim 13, wherein applying post-processing to the frequency low-band signal comprises processing the decoded sound signal through an inter-harmonic filter having the following transfer function:', 'yn = i x n - {xn -T + xn + T}', 'for inter-harmonic attenuation of the decoded sound signal, where xn is the decoded sound signal, yn is the inter-harmonic filtered decoded sound signal in a given sub-band, and 7 is a pitch delay of the decoded sound signal

19. A post-processing method as defined in claim 18, further comprising summing the unprocessed decoded sound signal and the inter- harmonic filtered frequency low-band signal to produce an output post- processed decoded sound signal.

20. A post-processing method as defined in claim 1 , wherein applying post-processing to at least one of the frequency sub-band signals comprises pitch enhancing the decoded sound signal using the following equation: n {l- n {in-THn+T}', 'where xn is the decoded sound signal, yn is the pitch enhanced decoded sound signal in a given sub-band, 7 is a pitch delay of the decoded sound signal, and a is a coefficient varying between 0 and 1 to control an amount of inter-harmonic attenuation of the decoded sound signal.

21. A post-processing method as defined in claim 20, comprising receiving the pitch delay 7 through a bitstream.

22. A post-processing method as defined in claim 20, comprising decoding the pitch delay Tfrom a received, encoded bitstream.

23. A post-processing method as defined in claim 20, comprising calculating the pitch delay 7 in response to the decoded sound signal for an improved pitch tracking.

24. A post-processing method as defined in claim 1 , wherein, during encoding, the sound signal is down-sampled from a higher sampling frequency to a lower sampling frequency, and wherein dividing the decoded sound signal into a plurality of frequency sub-band signals comprises up-sampling the decoded sound signal from the lower sampling frequency to the higher sampling frequency.

25. A post-processing method as defined in claim 24, wherein dividing the decoded sound signal into a plurality of frequency sub-band signals comprises sub-band filtering the decoded sound signal, and wherein the up- sampling of the decoded sound signal from the lower sampling frequency to the higher sampling frequency is combined to the sub-band filtering.

26. A post-processing method as defined in claim 24, comprising: band-pass filtering the decoded sound signal to produce a frequency upper-band signal, said band-pass filtering of the decoded sound signal being combined with up-sampling of the decoded sound signal from the lower sampling frequency to the higher sampling frequency; and post-processing the decoded sound signal and low-pass filtering the post-processed decoded sound signal to produce a frequency lower-band signal, said low-pass filtering of the post-processed decoded sound signal being combined with up-sampling of the post-processed decoded sound signal from the lower sampling frequency to the higher sampling frequency.

27. A post-processing method as defined in claim 26, further comprising adding the frequency upper-band signal with the frequency lower- band signal to form an output post-processed and up-sampled decoded sound signal.

28. A post-processing method as defined in claim 26, wherein postprocessing of the decoded sound signal comprises pitch enhancing the decoded sound signal to reduce an inter-harmonic noise in the decoded sound signal.

29. A post-processing method as defined in claim 28, wherein pitch enhancing the decoded sound signal comprises processing the decoded sound signal by means of the following equation:', '', 'where xn is the decoded sound signal, yn is the pitch enhanced decoded sound signal in a given sub-band, 7 is a pitch delay of the decoded sound signal, and a is a coefficient varying between 0 and 1 to control an amount of inter-harmonic attenuation of the decoded sound signal.

30. A post-processing method as defined in claim 1, wherein: dividing the decoded sound signal into a plurality of frequency sub-band signals comprises dividing the decoded sound signal into a frequency upper- band signal and a frequency lower-band signal; and applying post-processing to at least one of the frequency sub-band signals comprises post-processing the frequency lower-band signal.

31. A post-processing method as defined in claim 1 , wherein applying post-processing to said at least one of the frequency sub-band signals comprises: determining a pitch value of the decoded sound signal; calculating, in relation to the determined pitch value, a high-pass filter with a cut-off frequency below a fundamental frequency of the decoded sound signal; and processing the decoded sound signal through the calculated high-pass filter.

32. A device for post-processing a decoded sound signal in view of enhancing a perceived quality of said decoded sound signal, comprising: means for dividing the decoded sound signal into a plurality of frequency sub-band signals; and means for post-processing at least one of the frequency sub-band signals, but not all the frequency sub-band signals.

33. A post-processing device as defined in claim 32, further comprising adder means for summing the frequency sub-band signals, after postprocessing of said at least one frequency sub-band signal, to produce an output post-processed decoded sound signal.

34. A post-processing device as defined in claim 32, wherein the post- processing means comprises adaptive filter means supplied with the decoded sound signal.

35. A post-processing device as defined in claim 32, wherein the dividing means comprises sub-band filter means supplied with the decoded sound signal.

36. A post-processing device as defined in claim 32, wherein, for said at least one of the frequency sub-band signals: the post-processing means comprises an adaptive filter supplied with the decoded sound signal to produce an adaptively filtered decoded sound signal; and the dividing means comprises a sub-band filter supplied with the adaptively filtered decoded sound signal.

37. A post-processing device as defined in claim 32, wherein: the dividing means comprises:', '- a high-pass filter supplied with the decoded sound signal to produce a frequency high-band signal; and - a low-pass filter supplied with the decoded sound signal to produce a frequency low-band signal; and the post-processing means comprises:', '- a post-processor for post-processing the decoded sound signal prior to low-pass filtering the decoded sound signal through the low-pass filter.

38. A post-processing device as defined in claim 37, wherein the post processor comprises a pitch enhancer supplied with the decoded sound signal to produce a pitch enhanced decoded sound signal.

39. A post-processing device as defined in claim 38, further comprising a low-pass filter supplied with the decoded sound signal to produce a low-pass filtered decoded sound signal supplied to the pitch enhancer.

40. A post-processing device as defined in claim 37, further comprising an adder for summing the frequency high-band and low-band signals to produce an output post-processed decoded sound signal.

41. A post-processing device as defined in claim 32, wherein: the dividing means comprises:', '- a band-pass filter supplied with the decoded sound signal to produce a frequency upper-band signal; and', '- a low-pass filter supplied with the decoded sound signal to produce a frequency lower-band signal; and the post-processing means comprises:', '- a post-processor for post-processing the frequency lower-band signal.

42. A post-processing device as defined in claim 41 , wherein the postprocessor comprises a pitch filter supplied with the decoded sound signal to produce a pitch enhanced decoded sound signal supplied to the low-pass filter.

43. A post-processing device as defined in claim 41 , further comprising an adder for summing the frequency upper-band and lower-band signals to produce an output post-processed decoded sound signal.

44. A post-processing device as defined in claim 32, wherein: the dividing means comprises: - a low-pass filter supplied with the decoded sound signal to produce a frequency low-band signal; and the post-processing means comprises: - a post-processor for post-processing the decoded sound signal to produce a post-processed decoded sound signal supplied to the low-pass filter.

45. A post-processing device as defined in claim 44, wherein the postprocessor comprises an inter-harmonic filter supplied with the decoded sound signal to produce an inter-harmonic, attenuated decoded sound signal.

46. A post-processing device as defined in claim 45, wherein the postprocessor comprises a multiplier for multiplying the inter-harmonic, attenuated decoded sound signal by an adaptive pitch enhancement gain.

47. A post-processing device as defined in claim 45, further comprising a low-pass filter supplied with the decoded sound signal to produce a low-pass filtered decoded sound signal supplied to the inter-harmonic filter.

48. A post-processing device as defined in claim 44, further comprising an adder for summing the decoded sound signal and the frequency low-band signal to produce an output post-processed decoded sound signal.

49. A post-processing device as defined in claim 44, wherein the postprocessor comprises an inter-harmonic filter having the following transfer function:', 'yn = 2 x W _ 4 MR ~ rl + *" + rI', 'for inter-harmonic attenuating the decoded sound signal, where xn is the decoded sound signal, yn is the inter-harmonic filtered decoded sound signal in a given sub-band, and 7 is a pitch delay of the decoded sound signal.

50. A post-processing device as defined in claim 49, further comprising an adder for summing the unprocessed decoded sound signal and the inter- harmonic filtered frequency low-band signal to produce an output post- processed decoded sound signal.

51. A post-processing device as defined in claim 32, wherein the postprocessing means comprises a pitch enhancer of the decoded sound signal using the following equation:', '', 'where xn is the decoded sound signal, yn is the pitch enhanced decoded sound signal in a given sub-band, 7 is a pitch delay of the decoded sound signal, and a is a coefficient varying between 0 and 1 to control an amount of inter-harmonic attenuation of the decoded sound signal.

52. A post-processing device as defined in claim 51 , comprising means for receiving the pitch delay 7 through a bitstream.

53. A post-processing device as defined in claim 51 , comprising means for decoding the pitch delay from a received, encoded bitstream.

54. A post-processing device as defined in claim 51 , comprising means for calculating the pitch delay 7 in response to the decoded sound signal for an improved pitch tracking.

55. A post-processing device as defined in claim 32, wherein, during encoding, the sound signal is down-sampled from a higher sampling frequency to a lower sampling frequency, and wherein the dividing means comprises means for up-sampling the decoded sound signal from the lower sampling frequency to the higher sampling frequency.

56. A post-processing device as defined in claim 55, wherein the dividing means comprises sub-band filter means supplied with the decoded sound signal, and wherein the up-sampling means is combined with the sub- band filter means.

57. A post-processing device as defined in claim 55, wherein: - the post-processing means comprises: means for post-processing the decoded sound signal; and - the dividing means comprises: a band-pass filter supplied with the decoded sound signal to produce a frequency upper-band signal, said band-pass filter being combined with the up-sampling means; and a low-pass filter supplied with the post-processed decoded sound signal to produce a frequency lower-band signal, said low-pass filter being combined with the up-sampling means.

58. A post-processing device as defined in claim 57, further comprising an adder for summing the frequency upper-band signal with the frequency lower-band signal to form an output post-processed and up-sampled decoded sound signal.

59. A post-processing device as defined in claim 57, wherein the means for post-processing the decoded sound signal comprises means for pitch enhancing the decoded sound signal to reduce an inter-harmonic noise in the decoded sound signal.

60. A post-processing device as defined in claim 59, wherein the pitch enhancing means comprises means for processing the decoded sound signal by means of the following equation:', '', 'where xn is the decoded sound signal, yn is the pitch enhanced decoded sound signal in a given sub-band, 7 is a pitch delay of the decoded sound signal, and a is a coefficient varying between 0 and 1 to control an amount of inter-harmonic attenuation of the decoded sound signal.

61. A post-processing device as defined in claim 32, wherein: the dividing means comprises means for dividing the decoded sound signal into a frequency upper-band signal and a frequency lower-band signal; and the post-processing means comprises means for post-processing the frequency lower-band signal.

62. A post-processing device as defined in claim 32, wherein the postprocessing means comprises: means for determining a pitch value of the decoded sound signal; means for calculating, in relation to the determined pitch value, a high- pass filter with a cut-off frequency below a fundamental frequency of the decoded sound signal; and means for processing the decoded sound signal through the calculated high-pass filter.

63. A sound signal decoder comprising: an input for receiving an encoded sound signal; a parameter decoder supplied with the encoded sound signal for decoding sound signal encoding parameters; a sound signal decoder supplied with the decoded sound signal encoding parameters for producing a decoded sound signal; and a post processing device as recited in any of claims 32 to 62 for postprocessing the decoded sound signal in view of enhancing a perceived quality of said decoded sound signal.']