Two-way cluster voting to improve speaker diarisation performance

Speaker diarisation is the task of automatically segmenting audio data and providing speaker labels for the resulting regions of audio. A cluster-voting scheme is described which takes the output from two speaker diarisation systems and produces a new output which aims to have a lower speaker diarisation error rate (DER) than either input. The scheme works in two stages: the first produces a set of possible outputs which minimise a distance metric based on the DER; the second votes between these alternatives to give the final output. Decisions where the inputs agree are always passed to the output and those where the inputs differ are re-evaluated in the final voting stage. Results are presented on the 6-show RT-03 broadcast news evaluation data; they show that the DER can be reduced by 1.64% and 2.56% absolute using this method when combining the best two Cambridge University and the best two MIT Lincoln Laboratory diarisation systems respectively.