Effect of compression, digital noise reduction and directionality on envelope difference index, log-likelihood ratio and perceived quality
AbstractThe aim of the present study was to evaluate the use of the envelope difference index (EDI) and log-likelihood ratio (LLR) to quantify the independent and interactive effects of wide dynamic range compression, digital noise reduction and directionality, and to carry out selfrated quality measures. A recorded sentence embedded in speech spectrum noise at +5 dB signal to noise ratio was presented to a four channel digital hearing aid and the output was recorded with different combinations of algorithms at 30, 45 and 70 dB HL levels of presentation through a 2 cc coupler. EDI and LLR were obtained in comparison with the original signal using MATLAB software. In addition, thirty participants with normal hearing sensitivity rated the output on the loudness and clarity parameters of quality. The results revealed that the temporal changes happening at the output is independent of the number of algorithms activated together in a hearing aid. However, at a higher level of presentation, temporal cues are better preserved if all of these algorithms are deactivated. The spectral components speech tend to get affected by the presentation level. The results also indicate the importance of quality rating as this helps in considering whether the spectral and/or temporal deviations created in the hearing aid are desirable or not.
PlumX Metrics provide insights into the ways people interact with individual pieces of research output (articles, conference proceedings, book chapters, and many more) in the online environment. Examples include, when research is mentioned in the news or is tweeted about. Collectively known as PlumX Metrics, these metrics are divided into five categories to help make sense of the huge amounts of data involved and to enable analysis by comparing like with like.
Copyright (c) 2014 Chinnaraj Geetha, Puttabasappa Manjula
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.