Speech enhancement utilizing phase continuity between consecutive analysis windows

Download

index.pdf

Date

2011

Author

Mehmetcik, Erdal

Metadata

Show full item record

Item Usage Stats

174
views

69
downloads

It is commonly accepted that the induced noise on DFT phase spectrum has a negligible effect on speech intelligibility for short durations of analysis windows, as the early intelligibility studies pointed out. This fact is confirmed by recent intelligibility studies as well. Based on this phenomenon, classical speech enhancement algorithms do not modify DFT phase spectrum and only make changes in the DFT magnitude spectrum. However, in recent studies it is also indicated that these classical speech enhancement algorithms are not capable of improving the intelligibility scores of noise degraded speech signals. In other words, the contained information in a noise degraded signal cannot be increased by classical enhancement methods. Instead the ease of listening, i.e. quality, can be improved. Hence additional effort can be made to increase the amount of quality improvement using both DFT magnitude and DFT phase. Therefore if the performances of the classical methods are to be improved in terms of speech quality, the effect of DFT phase on speech quality needs to be studied. In this work, the contribution of DFT phase on speech quality is investigated through some simulations using an objective quality assessment criterion. It is concluded from these simulations that, the phase spectrum has a significant effect on speech quality for short durations of analysis windows. Furthermore, phase values of low frequency components are found to have the largest contribution to this quality improvement. Under the motivation of these results, a new enhancement method is proposed which modifies the phase of certain low frequency components as well as the magnitude spectrum. The proposed algorithm is implemented in MATLAB environment. The results indicate that the proposed system improves the performance of the classical methods in terms of speech quality.

Subject Keywords

Telecommunication.

URI

http://etd.lib.metu.edu.tr/upload/12613605/index.pdf
https://hdl.handle.net/11511/21073

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Interception techniques for direct sequence spread spectrum signals Karadeniz, Uygar; Baykal, Buyurman; Department of Electrical and Electronics Engineering (2005) In this work interception and spreading sequence estimation of Direct Sequence Spread Spectrum (DSSS) signals, in low signal to noise power ratios is discussed. For interception an approach based on autocorrelation fluctuations is employed and also symbol period is estimated from this interception process. Spreading sequence estimation is performed by using eigenanalysis of the correlation matrix and estimated symbol period. These approaches are applied on different kinds of DSSS signals including 3rd gener...
Waveform design for pulse doppler radar Ağırman, Handan; Severcan, Mete; Department of Electrical and Electronics Engineering (2005) This study is committed to the investigation of optimum waveforms for a pulse doppler radar which uses a non linear high power amplifier in the transmitter. The optimum waveform is defined as the waveform with the lowest peak and integrated side lobe level, the narrowest main lobe in its autocorrelation and the narrowest bandwidth in its spectrum. The Pulse Compression method is used in radar systems since it is more advantageous in terms of the resolution. Among all pulse compression methods, the main focu...
Investigation of gmpls applications in optical systems Göken, Burcu; Ergül, Rüyal; Department of Electrical and Electronics Engineering (2005) In this study, possible applications of label switching in large area, fully optical networks are investigated. The objective was to design a label assignment method by using Generalized Multi-Protocol Label Switching (GMPLS) concept to get an efficient optical network operation. In order to fulfill this objective, two new approaches were proposed: a label assignment method and a concatenated label structure. Label assignment method was designed to provide an efficient utilization of resources. Concatenated...
Design of an FM-CW radar altimeter Yetkil, Yaşar Barış; Demir, Şimşek; Department of Electrical and Electronics Engineering (2005) Frequency modulated continuous wave (FM-CW) radar altimeters are used in civil and military applications. Proximity fuses, automatic cruise control systems of cars, radar altimeter of planes are examples to these applications. The goal of this thesis is to present a method for altitude determination using an FM-CW radar. For this purpose principles of radars and FM-CW systems are studied and related subjects are inspected. After this inspection, algorithms for altitude determination are evaluated. Consequen...
Nonuform pulse repetition interval optimization for pulse doppler radars Mercan, Hasan; Tanık, Yalçın; Department of Electrical and Electronics Engineering (2004) In this thesis, a method of optimization of nonuniform pulse repetition interval for pulse Doppler radars is investigated. PRI jittering technique is used for the selection of inter-pulse intervals. An environment with white Gaussian noise and clutter interference is defined and applying generalized likelihood ratio test, a sufficient statistic function for the detection of the target is derived. The effect of jitter set selection on range and Doppler ambiguity resolution and clutter rejection is investigat...

Citation Formats

E. Mehmetcik, “Speech enhancement utilizing phase continuity between consecutive analysis windows,” M.S. - Master of Science, Middle East Technical University, 2011.