Acoustic Correlates of Speech when Under Stress: Research, Methods and Future Directions


  • Christin Kirchhübel University of York
  • David M. Howard University of York
  • Alex W. Stedmon University of Nottingham



Psychological Stress, Acoustic Analysis, Acoustic and Phonetic Correlates


The aim of this paper is to summarise the acoustical correlates of stress in speech by reviewing relevant empirical studies. Research into speech under stress faces several challenges including the difficulty in defining the concept of stress, limitations in collecting stressed speech experimentally and the problem of quantifying the type and level of stress induced, resulting in very limited comparability between various studies. In summarizing the previous work and evidence, these conceptual and methodological differences are addressed. Changes in respiration and muscle tension have repeatedly been evidenced to be physiological correlates of stress. Based on this, it may be expected that acoustic parameters such as fundamental frequency, intensity and speaking/articulation rate are affected by stress. In general, empirical findings support these predictions but inter-speaker variability must not be overlooked. It is argued that there is a need to move beyond these three parameters, taking into account for example, vowel formants and aspects of voice quality. It is also suggested that future research should aim to control the data gathering process in ways that are appropriate to allow for comparability of results between studies.

Author Biographies

Christin Kirchhübel, University of York

Christin Kirchhübel is a doctoral researcher in the Department of Electronics at the University of York, UK. Her PhD investigates the acoustic and phonetic correlates of deceptive speech. She has a BA in English Language and Linguistics from Lancaster University and an MSc in Forensic Speech Science from the University of York. Her research interests include forensic phonetics, sociophonetics and sociolinguistics.

David M. Howard, University of York

Professor David Howard BSc (Eng), PhD, CEng, FIET, FIOA, MAES (Head of the Department of Electronics, University of York) has written over 250 papers in the areas of voice, music and audio analysis and synthesis. He presented and co-presented the programs “Voice” and “Castrato” respectively for BBC-TV and has written two textbooks in the areas of acoustics, psychoacoustics and voice. David plays the organ and conducts the Vale of York Voices; a choir that sings Evensong in York Minster once a month.

Alex W. Stedmon, University of Nottingham

Dr Alex Stedmon FIEHF CPsychol CSci FRSA (Academic Director of Human Factors in the Faculty of Engineering at the University of Nottingham) has written over 100 publications reflecting a diverse career in industry and academia, focusing on: security, transport and novel interfaces (e.g. speech input). His PhD investigated human factors of speech input for real world and virtual reality applications and he has previously worked for the MoD on speech recognition research for military systems.



How to Cite

Kirchhübel, C., Howard, D. M., & Stedmon, A. W. (2011). Acoustic Correlates of Speech when Under Stress: Research, Methods and Future Directions. International Journal of Speech, Language and the Law, 18(1), 75–98.