Dr. Hendrik Husstedt and Marlitt Frenz B. Sc., Lübeck
Video 16 2017
“Analysis of noise reduction in situations with multiple signals from different directions”/h3>
Noise reduction has been part of signal processing in hearing aids for many years. The feature is intended to amplify the target signal, usually speech, and reduce interference signals. Technically, noise reduction efficiency can be quantified by increasing the signal-to-noise ratio (SNR). In a 2004 publication, Hagerman und Olofsson presented a method to measure the increase of SNR caused by noise reduction.
However, this method is limited to only one target and one interference signal. Complex situations, e.g. with multiple speakers and multiple noise sources, cannot be analysed using this procedure.
Therefore, in this presentation, an extension of the Hagerman and Olofsson method will be shown, making it possible to distinguish multiple target and interference signals from the same, or from different, directions. Successful implementation of the concept will be demonstrated using a measurement setup including eight speakers and up to nine different signals. Results show that the extended method is feasible, and that a comprehensive analysis of noise reduction, even in complex hearing situations with multiple target and interference signals, is also possible.