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Speech Enhancement with Factor-Graphs

Authors Irnberger, W.
Year 2003
Thesis Type Diploma thesis
Topic Audio Signal Processing
Keywords speech processing
Abstract In this diploma thesis I tried out to handle speech signals with the help of factor-graphs. The aim is to improve the audibility of speech in noisy backgrounds. For this the linear predictive coding (LPC) – model was already transformed into a factor-graph. This factor- graph was now changed in this diploma thesis to fit better to speech signals. Chapter 2 is a small introduction to factor-graphs, how to construct and compute them. In Chapter 3 the factor-graph of the linear predictive coding – model is introduced. The LPC is used to analyze and synthesize speech. Chapter 4 deals with the modifications of the factor-graph. A noise was modelled and the filter coefficients were modified to enhance the whole model. To calculate signals with the system in real-time a dynamic construction of the factor-graph was developed, which is described in Chapter 5. In Chapter 6 the modifications are tested and documented.
Supervisors Höldrich, R., Korl, S.