Change search
ReferencesLink to record
Permanent link

Direct link
Blekinge Institute of Technology, School of Engineering.
2013 (English)Independent thesis Advanced level (degree of Master (Two Years))Student thesis
Abstract [en]

In recent years a great deal of effort has been expended to develop methods that determine the quality of speech through the use of comparative algorithms. These methods are designed to calculate an index value of quality that correlates to a mean opinion score given by human subjects in evaluation sessions. In this work PESQ (ITU-T Recommendation P.862) which is the new ITU-T benchmarking for objective measurement of speech quality. In mobile phone acoustics, the presence of noise and room reverberation play a vital role in degrading the speech signal and therefore, spectral subtraction and Elko’s beamformer has been used for noise reduction. Weighted Overlap and Add method (WOLA) filter bank is used for frequency domain analysis of the speech signal. Elko’s algorithm is used for designing a differential microphone array, implemented by connecting two omni directional elements to form back-to-back cardioid directional microphones. The output from the Elko’s beamformer is then used as an input to spectral subtraction based on minimum statistics reducing further noise and to enhance the quality of the speech signal. The performance of this system is analysed by calculating the value of PESQ as a speech quality measure. The better the value the PESQ, the better is the output speech quality. Signal to Noise Ratio (SNR) is used to measure the amount of noise in the restored speech signal. Reverberation Index is also used to measure the amount of reverberation effect present in the restored speech signal.

Place, publisher, year, edition, pages
2013. , 67 p.
Keyword [en]
Acoustics, PESQ, ELKOS, Spectral Subtraction, WOLA, Reverberation
National Category
Signal Processing Probability Theory and Statistics Electrical Engineering, Electronic Engineering, Information Engineering
URN: urn:nbn:se:bth-5781Local ID: diva2:833183
Physics, Chemistry, Mathematics
Available from: 2015-04-22 Created: 2013-01-25 Last updated: 2015-06-30Bibliographically approved

Open Access in DiVA

fulltext(3893 kB)102 downloads
File information
File name FULLTEXT01.pdfFile size 3893 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
School of Engineering
Signal ProcessingProbability Theory and StatisticsElectrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 102 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 40 hits
ReferencesLink to record
Permanent link

Direct link