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Title Common principles of across-channel processing in monaural versus binaural hearing
Author Piechowiak, Tobias
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2005
Abstract The auditory sytem provides us with uncountable information about our surroundings that are crucial for our everday life as there are e.g. the ringing of a phone, the determination of the direction of an approaching car or understanding speech which represents information of another human beeing. There are limits to our capability to perceive sounds as the fact that one sound can be masked by another one which means that one sound's detectability can be decreased by the presence of another sound with similar spectal, spatial and timing properties. However, several phenomena have been investigated that facilitate the perception of masked sound as there are the binaural phenomenon called binaural masking level difference (BMLD) and comodulation masking release (CMR).\\ This thesis investigates possible common principles of the mechanisms underlying binaural masking level difference (BMLD) and comodulation masking release (CMR) in two different approaches. In the first chapter, an introduction to the theoretical background of the topics of this thesis is presented. In chapter 2, the influence of auditory grouping on the amount of BMLD is measured and compared with the influence of grouping on CMR, investigated earlier in several studies e.g. {Dau \it{et al.}} (2003). The sensitivity of BMLD and CMR to grouping paradigms could be a common property of both binaural and monaural processing of sounds and since it is assumed that auditory grouping is originating at central stages of processing it could give a hint that both BMLD and CMR occur at least partly at a higer processing stage and that they may underly similar processes.\\ In the last chapter the nature of this possible common process is more specified by introducing a model to predict CMR on the basis of an equalization-cancellation (EC) model. This model was first mentioned to account for BMLD data and an EC approach was also used to develop a more general model that can accoount for a large variety of binaural detection data. Several exeriments are performed by human subjects as well as by the processing model as an ideal observer in a three-interval 3-alternatve choice (3-IFC) procedure to validate the performance of the EC-CMR model.
Pages 58
Fulltext
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Admin Creation date: 2009-09-30    Update date: 2009-09-30    Source: dtu    ID: 250601    Original MXD