Applying Vocal Tract Length Normalization to Meeting Recordings
View/ Open
Date
2005Author
Garau, Giulia
Renals, Steve
Hain, Thomas
Metadata
Abstract
Vocal Tract Length Normalisation (VTLN) is a commonly used
technique to normalise for inter-speaker variability. It is based
on the speaker-specific warping of the frequency axis, parameterised
by a scalar warp factor. This factor is typically estimated
using maximum likelihood. We discuss how VTLN may
be applied to multiparty conversations, reporting a substantial
decrease in word error rate in experiments using the ICSI meetings
corpus. We investigate the behaviour of the VTLN warping
factor and show that a stable estimate is not obtained. Instead it
appears to be influenced by the context of the meeting, in particular
the current conversational partner. These results are consistent
with predictions made by the psycholinguistic interactive
alignment account of dialogue, when applied at the acoustic and
phonological levels.