The dynamics of indexical information in speech and its role in speech communication and speaker recognition

Responsible: Volker Dellwo    
Duration of the project: Aug. 2019-Dec 2023 

Project Description:

The aim of the present project is to understand the dynamics of indexical information by examining speech from human interaction. For this we will investigate how indexical information varies (a) within utterances and (b) speaking styles and (c) what effects this variability has on speaker recognition. The results will show to what degree speakers have control over indexical information to either reveal or suppress their individuality in speech communication situations. To reach these aims we will sample a large homogenous population of human voices (~500 speakers) in which individuals will be recorded varying their speaking styles in situations where individuality plays a role (e.g. charismatic, deceptive, clear, or computer directed speech). Subsequently, this data will be analysed with computer modelling to understand the variability of indexical information between speaking styles in individuals in respect of the population mean. Using machine and human speaker recognition experiments we will test the effects that indexical variability has on the recognizability of speakers’ voices under certain speaking styles. Results will be crucial to the understanding of the role of indexical information for human-human and human-machine speech communication. They will affect the way we think about linguistic and speaker specific information processing alike and have an impact on the areas of psychology, behavioural biology and/or neurosciences that aim at understanding how humans perceive and process speech as well as speech technology and forensic phonetic applications where different samples most typically involve differences in speaking style. Finally, knowledge about the role of individuality information in speech will be important for understanding evolutionary processes of speech communication, a research area of increasing strength at UZH and across Switzerland.  

Publications (or conference presentation):

Dellwo, V., Pellegrino, E., He, L., and Kathiresan, T. (2019) “The Dynamics of Indexical Information in Speech: Can recognizability be controlled by the speaker?” Acta Universitatis Carolinae, Philologica, (2019)2, 57-75.


Keywords: indexical information in speech, automatic speaker recognition, human voice processing, speaking styles

Funding source(s): Swiss National Science Foundation

Partners: Moritz. Daum, Martin Meyer, Urs Maurer, Rushen Shi, Anil Alexander