An improved subband noise reduction technique is proposed for two-microphone voice communication systems. The technique aims to enhance the speech quality by utilising a subband structure with different noise reduction schemes for different frequency bands. In the low-frequency band where dominant cues of speech spectral components are usually located and the noise signals from the two channels are mainly correlated, the spectral subtraction method, together with a new variable noise subtraction parameter, is employed so that the noise attenuation performance and speech distortion are controllable. In the high-frequency band where less-dominant frequency information of speech spectrum is located, the modified cross-spectral subtraction technique is utilised to remove the high-frequency decorrelated noise spectral components. Extensive comparisons among various noise reduction techniques based on computer simulations demonstrate that the proposed two-microphone subband noise reduction scheme achieves excellent noise attenuation performance while preserving the speech quality.

References

1. 1)
  - 27. Jeub, M., Herglotz, C., Nelke, C., Beaugeant, C., Vary, P.: ‘Noise reduction for dual-microphone mobile phones exploiting power level differences’. Proc. Int. Conf. Acoustics, Speech, and Signal Processing (ICASSP), Kyoto, Japan, March 2012, pp. 1693–1696.
2. 2)
  - 22. McCowan, I.A., Bourlard, H.: ‘Microphone array post-filter for diffuse noise field’. Proc. Int. Conf. Acoustics, Speech, and Signal Processing (ICASSP), Orlando, USA, May 2002, pp. 905–908.
3. 3)
  - 28. Vaseghi, S.V.: ‘Advanced digital signal processing and noise reduction’ (Wiley, 2000, 2nd edn.), Chapter 11.
4. 4)
  - 33. ‘Methods for subjective determination of transmission quality’, ITU-T Recommendation, 1996, p. 800.
5. 5)
  - 6. Wightman, F.L., Kistler, D.J.: ‘The dominant role of low-frequency interaural time differences in sound localization’, J. Acoust. Soc. Am., 1992, 91, (3), pp. 1648–1661 (doi: 10.1121/1.402445).
6. 6)
  - 9. Li, C., Liu, W.J.: ‘A novel multi-band spectral subtraction method based on phase modification and magnitude compensation’. Proc. Int. Conf. Acoustics, Speech, and Signal Processing (ICASSP), Prague, Czech Republic, May 2011, pp. 4760–4763.
7. 7)
  - 29. ‘TIMIT (Texas Instruments (TI) and Massachusetts Institute of Technology (MIT)) speech database’, which is sponsored by DARPA (The Defense Advanced Research Projects Agency of the United States Department of Defense), http://www.ldc.upenn.edu/, accessed June 2013.
8. 8)
  - 21. Zelinski, R.: ‘A microphone array with adaptive post-filtering for noise reduction in reverberant rooms’. Proc. Int. Conf. Acoustic, Speech, and Signal Processing (ICASSP), New York, USA, April 1988, pp. 2578–2581.
9. 9)
  - 23. Dorbecker, M., Ernst, S.: ‘Combination of two-channel spectral subtraction and adaptive wiener post-filtering for noise reduction and dereverberation’. Proc. European Signal Processing Conference (EUSIPCO), Trieste, Italy, September 1996, pp. 995–998.
10. 10)
  - 20. Rahmani, M., Akbari, A., Ayad, B., Lithgow, B.: ‘Noise cross PSD estimation using phase information in diffuse noise field’, Signal Process., 2009, 89, (5), pp. 703–709 (doi: 10.1016/j.sigpro.2008.10.020).
11. 11)
  - 25. Maj, J.B., Wouters, J., Moonen, M.: ‘Noise reduction results of an adaptive filtering technique for dual-microphone behind-the-ear hearing aids’, Ear & Hearing: J. Am. Audit. Soc., 2004, 25, (3), pp. 215–229 (doi: 10.1097/01.AUD.0000130794.28068.96).
12. 12)
  - S.F. Boll . Suppression of acoustic noise in speech using spectral subtraction. IEEE Trans. Acoust., Speech, Signal Process. , 113 - 120
13. 13)
  - 32. ‘Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs’, ITU-T Recommendation, 2001, p. 862.
14. 14)
  - 26. Yousefian, N., Kokkinakis, K., Loizou, P.C.: ‘A coherence-based algorithm for noise reduction in dual-microphone applications’. Proc. European Signal Processing Conference (EUSIPCO), Aalborg, Denmark, August 2010, pp. 1904–1908.
15. 15)
  - 14. Li, J., Akagi, M., Suzuki, Y.: ‘Extension of the two-microphone noise reduction method for binaural hearing aids’. Proc. Int. Conf. Audio, Language, and Image Processing (ICALIP), Shanghai, China, July 2008, pp. 97–101.
16. 16)
  - 30. ‘NOISEX-92: database of recording of various noises’, http://sipl.technion.ac.il/Info/Downloads_DataBases_NoiseX92_e.shtml, accessed June 2013.
17. 17)
  - C. Plapous , C. Marro . Improved signal-to-noise ratio estimation for speech enhancement. IEEE Trans. Speech Audio Process. , 6 , 2098 - 2108
18. 18)
  - 8. Kamath, S.D., Loizou, P.C.: ‘A multi-band spectral subtraction method for enhancing speech corrupted by colored noise’. Proc. Int. Conf. Acoustics, Speech, and Signal Processing (ICASSP), Orlando, USA, May 2002, pp. IV–4164.
19. 19)
  - 18. Rahmani, M., Akbari, A., Ayad, B., Mazoochi, M., Moin, M.S.: ‘A modified coherent based method for dual microphone speech enhancement’. Proc. Int. Conf. Signal Processing and Communications (ICSPC), Dubai, United Arab Emirates, November 2007, pp. 225–228.
20. 20)
  - Y. Ephraim , D. Malah . Speech enhancement using a minimum mean-square error short-time spectral amplitude estimator. IEEE Trans. Acoust. Speech Signal Process. , 6 , 1109 - 1121
21. 21)
  - 16. Guerin, A., Bouquin-Jeannes, R.L., Faucon, G.: ‘A two-sensor noise reduction system: applications for hands-free car kit’, EURASIP J. Appl. Signal Process., 2003, 2003, (11), pp. 1125–1134 (doi: 10.1155/S1110865703305098).
22. 22)
  - 19. Zamani, B., Rahmani, M., Akbari, A.: ‘Residual noise control for coherence based dual microphone speech enhancement’. Proc. Int. Conf. Computer and Electrical Engineering (ICCEE), Phuket, Thailand, March 2008, pp. 601–605.
23. 23)
  - 2. Chung, K., Zeng, F.G., Waltzman, S.: ‘Utilizing hearing aid directional microphones and noise reduction algorithms to improve speech understanding and listening preferences for cochlear implant users’, Int. Congress Ser., 2004, 1273, pp. 89–92 (doi: 10.1016/j.ics.2004.08.005).
24. 24)
  - 12. Chen, J., Benesty, J., Huang, Y., Doclo, S.: ‘New insights into the noise reduction Wiener filter’, IEEE Trans. Audio Speech Lang. Process., 2006, 14, (4), pp. 1218–1234 (doi: 10.1109/TSA.2005.860851).
25. 25)
  - 5. Thoonsaengngam, R., Tangsangiumvisai, N.: ‘The a priori SDR estimation technique with reduced speech distortion for acoustic echo and noise suppression’, IEICE Trans. Commun., 2009, E92-B, (10), pp. 3022–3033 (doi: 10.1587/transcom.E92.B.3022).
26. 26)
  - 17. Zhang, X., Jia, Y.: ‘A soft-decision based noise power cross power spectral density estimation for two-microphone speech enhancement systems’. Proc. Int. Conf. Acoustics, Speech, and Signal Processing (ICASSP), Philadelphia, USA, April 2005, pp. 813–816.
27. 27)
  - 13. Li, J., Akagi, M., Suzuki, Y.: ‘A two-microphone noise reduction method in highly non-stationary multiple noise-source environments’, IEICE Trans. Fundam., 2008, E91-A, (6), pp. 1337–1346 (doi: 10.1093/ietfec/e91-a.6.1337).
28. 28)
  - 11. Esch, T., Vary, P.: ‘Efficient musical noise suppression for speech enhancement systems’. Proc. Int. Conf. Acoustic, Speech, and Signal Processing (ICASSP), Taipei, Taiwan, April 2009, pp. 4409–4412.
29. 29)
  - 10. Hayashi, S., Inukai, H., Suguimoto, M.: ‘A subtractive-type speech enhancement using the perceptual frequency-weighting function’, IEICE Trans. Fundam., 2009, E92-A, (1), pp. 226–234 (doi: 10.1587/transfun.E92.A.226).
30. 30)
  - 15. Azirani, A.A., Bouquin-Jeannes, R.L., Faucon, G.: ‘Enhancement of speech degraded by coherent and incoherent noise using cross-spectral subtraction’, IEEE Trans. Speech Audio Process., 1997, 5, (5), pp. 484–487 (doi: 10.1109/89.622576).
31. 31)
  - 7. Berouti, M., Schwartz, R., Makhoul, J.: ‘Enhancement of speech corrupted by acoustic noise’. Proc. Int. Conf. Acoustics, Speech, and Signal Processing (ICASSP), Washington, USA, April 1979, pp. 208–211.
32. 32)
  - 31. Enqing, D., Guizhong, L., Yatong, Z., Yu, C.: ‘Voice activity detection based on short-time energy and noise spectrum adaptation’. Proc. Int. Conf. Signal Processing (ICSP), Beijing, China, October 2002, pp. 464–467.
33. 33)
  - 24. Maj, J.B., Moonen, M., Wouters, J.: ‘SVD-based optimal filtering technique for noise reduction in hearing aids using two microphones’, EURASIP J. Appl. Signal Process., 2002, 2002, (4), pp. 432–443 (doi: 10.1155/S1110865702000690).

Two-microphone subband noise reduction scheme with a new noise subtraction parameter for speech quality enhancement

References

Related content