1The Acoustic Universal Structure in Speech and Its Correlation to Para-linguistic Information in Speech

Speech acoustics inevitably carries non-linguistic information such as age, gender, speaker, microphone, line, room, and so on. These kinds of information is nothing but noise if linguis-tic and/or para-linguistic information in speech is considered. A novel method of acoustic representation of speech is proposed in this paper, which has no dimensions of the static and inevitable non-linguistic information. The representation is realized by mathematically interpreting a claim of Saussure, father of linguistics and structuralism, based on information theory and by implementing structural phonology, a part of linguistics, on physics. Speech events are modeled probabilistically as distributions, distance between two events is calcu-lated based on information theory, and an entire set of the events are captured relatively as a structure. The resulting structure is shown to have no dimensions of the non-linguistic information because multiplicative and linear transformational distortions are geometrically interpreted as shift and rotation of the structure, respectively. Therefore, the structure is considered to transmit only the linguistic and para-linguistic information. In this paper, size of the structure is investigated and several experiments show that the size can be interpreted as magnitude of articulatory e®orts made during speech production.