ISCA Archive Interspeech 2016
ISCA Archive Interspeech 2016

Automated Pause Insertion for Improved Intelligibility Under Reverberation

Petko N. Petkov, Norbert Braunschweiler, Yannis Stylianou

Speech intelligibility in reverberant environments is reduced because of overlap-masking. Signal modification prior to presentation in such listening environments, e.g., with a public announcement system, can be employed to alleviate this problem. Time-scale modifications are particularly effective in reducing the effect of overlap-masking. A method for introducing linguistically-motivated pauses is proposed in this paper. Given the transcription of a sentence, pause strengths are predicted at word boundaries. Pause duration is obtained by combining the pause strength and the time it takes late reverberation to decay to a level where a target signal-to-late-reverberation ratio criterion is satisfied. Considering a moderate reverberation condition and both binary and continuous pause strengths, a formal listening test was performed. The results show that the proposed methodology offers a significant intelligibility improvement over unmodified speech while continuous pause strengths offer an advantage over binary pause strengths.