Analyzing the effects on the internal signal-to-noise ratio for bilateral hearing-aid systems configured for asymmetric processing

Authors

  • Fredrik Gran GN ReSound A/S, Ballerup, Denmark
  • Jesper Udesen GN ReSound A/S, Ballerup, Denmark
  • Tobias Piechowiak GN ReSound A/S, Ballerup, Denmark
  • Andrew B. Dittberner GN ReSound North America, Bloomington, MN, USA

Abstract

This paper investigates how bilateral hearing-aid systems configured to perform asymmetric processing affect the internal signal-to-noise ratio (SNR) in the auditory system. Here, an asymmetric hearing-instrument (HI) system is characterized by directional noise reduction in the instrument in one ear whereas the contra-lateral device is adjusted for omni mode processing. The Equalization and Cancellation model is used to evaluate the internal SNR of the auditory system. Two reference conditions were also created, a system with directionality in both HI, and one with omni-mode processing in both HI. A speaker was placed to the front, and another speaker was placed at the side. In the first experiment, the target was assumed to be in the front direction and the noise was assumed to be coming from the side. Here, it was shown that the asymmetric system provided the same SNR as the system with directionality in both HI. The noise and target positions were interchanged and the experiment was repeated. In this case, the asymmetric system provided similar SNR as the system with omni-mode processing in both HI, which for this test condition provided a better SNR than the system with directionality in both HI.

References

Bentler, R.A., Egge, J.L., Tubbs, J.L., and Dittberner, A.B. (2004). “Quantification of directional benefit across different polar response patterns,” J. Am. Acad. Audiol., 15, 649-659.

Beutelmann, R., and Brand, T. (2006). “Prediction of speech intelligibility in spatial noise and reverberation for normal-hearing and hearing impaired listeners,” J. Acoust. Soc. Am., 120, 331-342.

Cord, M., Surr, R., Walden, B., and Dittberner, A.B. (2005). “Asymmetric directional microphone fittings,” American Academy of Audiology 17th Annual Convention, Washington D.C.

Culling, J.F., Hawley, M.L., and Litovsky, R.Y. (2004). “The role of head induced interaural time and level differences in the speech reception threshold for multiple interferring sound sources,” J. Acoust. Soc. Am., 116, 1057-1065.

Durlach, N.I. (1960). “Note on the equalization and cancellation theory of binaural masking level differences,” J. Acoust. Soc. Am., 32, 1075-1076.

Durlach, N.I. (1963). “Equalization and cancellation theory of binaural masking level differences,” J. Acoust. Soc. Am., 35, 1206-1218.

Hawley, M.L., Litovsky, R.Y., and Culling, J.F. (2004). “The benfit of binaural hearing in a cocktail party: Effect of location and type of interferer,” J. Acoust. Soc. Am., 115, 833-843.

Hornsby, B.W.Y., and Ricketts, T.A. (2007). “Effects of noise source configuration on directional benefit using symmetric and asymmetric directional hearing aid fittings,” Ear Hearing, 28, 177-186.

Kock, W.E. (1950). “Binaural localization and masking,” J. Acoust. Soc. Am., 22, 801-804.

Proakis, J.G., and Salehi, M. (1994). Communcation Systems Engineering (Prentice Hall).

Ricketts, T., and Dittberner, A.B. (2002). “Directionality amplification for improved signal-to-noise ratio: Strategies, measurements and limitations,” in Hearing Aids: Standards, Options and Limitations, 2nd ed. Edited by M. Valente, pp. 274-346.

Wan, R.W., Durlach, N.I., and Colburn, H.S. (2010). “Application of an extended equalization-cancellation model to speech intelligibility with spatially distributed maskers,” J. Acoust. Soc. Am., 128, 3678-3690.

Zurek, P.M. (1992). “Binaural advantages and directional effects in speech intelligibility,” in Acoustical Factors affecting Hearing Aid Performance, 2nd ed. Edited by G.A. Studebaker and I. Hochberg (Allyn and Bacon, Boston), pp. 255-276.

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Published

2013-12-15

How to Cite

Gran, F., Udesen, J., Piechowiak, T., & Dittberner, A. B. (2013). Analyzing the effects on the internal signal-to-noise ratio for bilateral hearing-aid systems configured for asymmetric processing. Proceedings of the International Symposium on Auditory and Audiological Research, 4, 287–294. Retrieved from https://proceedings.isaar.eu/index.php/isaarproc/article/view/2013-31

Issue

Vol. 4 (2013): Auditory Plasticity - Listening with the Brain

Section

2013/5. Design and evaluation of hearing-aid signal processing

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