Skip to main content

A Method to Measure the Effect of Noise Reduction Algorithms Using Simultaneous Speech and Noise


The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

Most hearing impairments reduce the ability to understand speech in the presence of background noise. Therefore, there is a great need to enhance the signal-to-noise ratio (S/N) in the hearing aid. It is, however, difficult to estimate the improvement in technical terms. No standardised methods are offered. Our approach is to present speech and noise simultaneously and make two measurements, one of them with the noise phase reversed. Taking the sum of the corresponding two output signals, or the difference, the output speech or the output noise can be extracted. Thus the gain can be calculated for each of them, although they are present at the same time and influence the signal processing of the hearing aid in a normal way. Five different hearing aids were tested with various speech and noise signals and S/Ns. Noise reduction up to 4 dB was measured with noise reduction algorithms (NRAs) activated. The NRAs in the hearing aids measured were more efficient at positive S/N and almost not useful at negative S/N at the particular levels used in the experiment. Fast compression can also influence the S/N.

Document Type: Research Article

Publication date: March 1, 2004

More about this publication?
  • Acta Acustica united with Acustica, published together with the European Acoustics Association (EAA), is an international, peer-reviewed journal on acoustics. It publishes original articles on all subjects in the field of acoustics, such as general linear acoustics, nonlinear acoustics, macrosonics, flow acoustics, atmospheric sound, underwater sound, ultrasonics, physical acoustics, structural acoustics, noise control, active control, environmental noise, building acoustics, room acoustics, acoustic materials, acoustic signal processing, computational and numerical acoustics, hearing, audiology and psychoacoustics, speech, musical acoustics, electroacoustics, auditory quality of systems. It reports on original scientific research in acoustics and on engineering applications. The journal considers scientific papers, technical and applied papers, book reviews, short communications, doctoral thesis abstracts, etc. In irregular intervals also special issues and review articles are published.
  • Editorial Board
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Information for Advertisers
  • Online User License
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content