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Hearing Voices: Sound, Technology, and Expert Listening in the Legal Arena

Michael Mopas, Associate Professor, Department of Sociology and Anthropology, Carleton University

Published April 20, 2018 by Technologies of Justice.

Michael Mopas presented a talk titled Hearing Voices: Sound, Technology, and Expert Listening in the Legal Arena during a session on surveillance, privacy and security in the digital era at the Technologies of Justice Conference. The session took place on January 26, 2018, at the University of Ontario Institute of Technology.



Mopas spoke on data collection from sound and auditory data technologies and how they are used in the courtroom. The discussion included information on current and future smart technology and recording devices as well as how auditory data is used in criminal and civil cases.

Mopas raised three main questions:

  • How does law attend to and make sense of sound?
  • How do sound experts influence what triers, in fact, hear at trial?
  • Who are the authoritative or expert listeners of sound?

Mopas explained that there is an increasing number of cases where identities are determined based on voice recording, citing aural or spectrographic evidence and automatic speaker recognition. He outlined these techniques and how they are used in court. He also pointed out issues with these techniques as well as other technologies being used, and discussed the chance of probability versus definitive claims when using auditory evidence in trials. He showed how there are many cases of what one would call 'Black Box Technology' where people are putting all of their confidence in software to diagnose and determine auditory data; this software can be fallible or even untested in some circumstances. He illustrated certain cases in which there have even been conflicts of interest in expert witness audio cases because of a financial interest in the software used.

Mopas concluded that 'less human' is not equal to 'less subjective.' He proposed that the unscientific opinion of regular witnesses and scientific opinion of expert witnesses can both be fallible, and they must both be regarded with equal amounts of skepticism and belief.