The analysis of Acoustic Phonetic Data: exploring differences in the spoken Romance languages
Davide Pigoli, Pantelis Zenon Hadjipantelis, John Coleman, John A. D. Aston · arXiv (Cornell University) · 2015
The process of change, particularly understanding the historical and geographical spread, from older to modern languages has long been studied from the point of view of textual changes and phonetic transcriptions. However, it is somewhat more difficult to analyze these from an acoustic point of view, although this is likely to be the dominant method of transmission rather than through written records. Here, we propose a novel approach to the analysis of acoustic phonetic data, where the aim will be to model statistically speech sounds. In particular, we explore phonetic variation and change using a time-frequency representation, namely the log-spectrograms of speech recordings. After preprocessing the data to remove inherent individual differences, we identify time and frequency covariance functions as a feature of the language; in contrast, the mean depends mostly on the particular word that has been uttered. We build models for the mean and covariances (taking into account the restrictions placed on the statistical analysis of such objects) and use this to define a phonetic transformation that allows us to model how an individual speaker would sound in a different language, allowing the exploration of phonetic differences between languages. Finally, we map back these transformations to the domain of sound recordings, allowing us to listen to statistical analysis. The proposed approach is demonstrated using the recordings of the words corresponding to the numbers from one to ten as pronounced by speakers from five different Romance languages.