Article  |   June 2006
Comparison of Performance on the Hearing in Noise Test Using Directional Microphones and Digital Noise Reduction Algorithms
Author Affiliations & Notes
  • Stacie Nordrum
    Northwestern University, Evanston, IL
  • Susan Erler
    Northwestern University, Evanston, IL
  • Dean Garstecki
    Northwestern University, Evanston, IL
  • Sumitrajit Dhar
    Northwestern University, Evanston, IL
  • Contact author: Sumit Dhar, Northwestern University, 2240 Campus Drive, Evanston, IL 60208-2952. Email: s-dhar@northwestern.edu
Hearing Disorders / Hearing Aids, Cochlear Implants & Assistive Technology
Article   |   June 2006
Comparison of Performance on the Hearing in Noise Test Using Directional Microphones and Digital Noise Reduction Algorithms
American Journal of Audiology June 2006, Vol.15, 81-91. doi:10.1044/1059-0889(2006/010)
History: Accepted 13 Feb 2006 , Received 15 Oct 2005 , Revised 25 Dec 2005
American Journal of Audiology June 2006, Vol.15, 81-91. doi:10.1044/1059-0889(2006/010)
History: Accepted 13 Feb 2006 , Received 15 Oct 2005 , Revised 25 Dec 2005

Purpose: Difficulty understanding speech in background noise is one of the most common complaints of hearing aid users. In modern hearing aids, directional microphones (d-mics) are considered the method of choice in improving signal-to-noise ratio, with demonstrated improvement in speech-perception-in-noise tasks. On the other hand, digital noise reduction (DNR) algorithms, in commercially available products, are considered to provide comfort but not significant assistance in improving speech perception in noise. In practice, these 2 technologies are often used in conjunction, but few studies have evaluated their interaction and the resultant effect on speech perception in noise. The purpose of this study was to evaluate the effect on speech performance of using d-mics and DNR in isolation as well as in conjunction in the presence of background noise.

Method: This study evaluates the performance of 16 experienced adult hearing aid users on the Hearing in Noise Test when each technology was activated independently and then simultaneously in 4 commercially available hearing aids.

Result: Approximately 50% of our participants performed better with both d-mics and DNR activated in conjunction, while the other 50% performed best in the d-mic-only condition. When considering statistically significant differences in performance only, a reduction or improvement in performance was observed in 17% and 14% of the conditions, respectively.

Conclusion: A direction for further research would be to identify predictive variables that could help the audiologist determine an individual’s preference a priori.

Order a Subscription
Pay Per View
Entire American Journal of Audiology content & archive
24-hour access
This Article
24-hour access

Related Articles

An Evidence-Based Systematic Review of Directional Microphones and Digital Noise Reduction Hearing Aids in School-Age Children With Hearing Loss
American Journal of Audiology December 2012, Vol.21, 295-312. doi:10.1044/1059-0889(2012/12-0014)
Ear Asymmetries and Asymmetric Directional Microphone Hearing Aid Fittings
American Journal of Audiology December 2011, Vol.20, 111-122. doi:10.1044/1059-0889(2011/10-0035)
Can Behavioral Speech-In-Noise Tests Improve the Quality of Hearing Aid Fittings?
Perspectives on Audiology November 2011, Vol.7, 8-14. doi:10.1044/poa7.1.8
Objective and Subjective Hearing Aid Assessment Outcomes
American Journal of Audiology December 2007, Vol.16, 118-129. doi:10.1044/1059-0889(2007/016)
The Effects of Changes in Head Angle on Auditory and Visual Input for Omnidirectional and Directional Microphone Hearing Aids
American Journal of Audiology June 2003, Vol.12, 41-51. doi:10.1044/1059-0889(2003/009)