Baseline Systems

Taking as a reference the blocks diagram in figure 3.5, experiments were conducted on three of the main blocks, namely the filter&sum module, the speech/non-speech module and the mono-channel speaker diarization module. For each block a baseline was defined to suit its characteristics and to allow for the development of its optimum parameters selection. The initial Wiener filtering of the signal was not analyzed as it was used without modification from its original implementation outside of the scope of this thesis.

The baseline system used for the experiments in the diarization module and in the speech/non speech module corresponds to a modified version of the broadcast news system presented for the NIST RT04f evaluation as described in section 3.1. This corresponds to a mono-channel system (or Single Distant Microphone, SDM, in the meetings domain) with the following main differences from RT04f:

The baseline system used for experiments on the beamforming module is composed of the submission to RT06s NIST evaluation campaign. This contains all the modules as explained in section 5.2 and their parameters optimized using a subset of 10 meetings from the development data available for RT06s.

user 2008-12-08