The SRI System for the NIST OpenSAD 2015 Speech Activity Detection Evaluation

In this paper, we present the SRI system submission to the NIST OpenSAD 2015 speech activity detection (SAD) evaluation. We present results on three different development databases that we created from the provided data. We present system-development results for feature normalization; for feature fusion with acoustic, voicing, and channel bottleneck features; and finally for SAD bottleneck-feature fusion. We present a novel technique called test adaptive calibration, which is designed to improve decision-threshold selection for each test waveform. We present unsupervised test adaptation of the fusion component and describe its tight synergy to the test adaptive calibration component. Finally, we present results on the evaluation test data and show how the proposed techniques lead to significant gains on channels unseen during training.