A Linear-Scaling Approach to Speaker Variability in Poly-segmental Formant Ensembles

Abstract

A linear-scaling approach is introduced for handling acoustic-phonetic manifestations of inter-speaker differences. The approach is motivated (i) by the similarity commonly observed amongst formant-frequency patterns resulting from different speakers’ productions of the same utterance, and (ii) by the fact that there are linear-scaling properties associated with similarity. In methodological terms, formant patterns are obtained for a set of segments selected from a fixed utterance, which we call poly-segmental formant ensembles. Linear transformations of these ensembles amongst different speakers are then sought and interpreted as a set of scaling relations. Using multi-speaker data based on Australian English “hello”, it is shown that the transformations afford a significant reduction of inter-speaker dissimilarity by inverse similarity. The proposed approach is thus able to unlock regularity in formant-pattern variability from speaker to speaker, without prior knowledge of the exact causes of the speaker differences manifested in the data at hand.