The presence of babble noise is one of the most difficult environments to sustain speech system performance. This study focuses on acoustic and perceptual analyses of babble. The acoustic variability of babble is analyzed as a function of the number of speakers in babble. The concept of acoustic volume is proposed and it is shown that the acoustic volume reduces as the number of speakers in babble increase. This framework is evaluated using over 40 hours of simulated babble from SWITCHBOARD corpus. It is observed that the acoustic volume does not change significantly when there are 4 or more speakers in babble. It is also seen that with an increase in the number of speakers in babble, there is an uneven spread of data in the acoustic space due to mixing of multi-speaker content. This study provides a framework to better understand the babble environment, enabling us to improve the formulation of reliable algorithms for robust speech systems.
Bibliographic reference. Krishnamurthy, Nitish / Ikeno, Ayako / Hansen, John H. L. (2008): "Babble speech: acoustic and perceptual variability", In INTERSPEECH-2008, 1040-1043.