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  • Oral evidence, both through examination in chief and cross-examination is an important source of evidence in court hearings.
  • The adoption of video conferencing (‘AVL’) has raised concerns since the 1990s as to whether oral evidence could be adduced effectively. The COVID-19 pandemic and the expanded use of AVL brought these issues to the fore.
  • When the AVL clearly fails, an online hearing cannot continue. However, rather than failing there may be a degradation in quality of the audio or video. A growing body of psychological research provides an important source of guidance for courts as to the impact of degradation in quality on witness examination.

Oral evidence, both through examination in chief and cross-examination is an important source of evidence in court hearings. In particular, where there are contested facts the reliability, credibility and veracity of the witness will be important. However the High Court in Fox v Percy (2003) 214 CLR 118; [2003] HCA 22, while accepting that a trial judge may draw on their impression of the credibility of witnesses in reaching their decision, also warned there are ‘dangers [in] too readily drawing conclusions about truthfulness and reliability solely or mainly from the appearance of witnesses’ (at [30]).

With this general admonishment in mind, oral evidence may now be given online rather than in person. The adoption of video conferencing, usually referred to as an audio visual link (‘AVL’), which may involve a witness testifying using audio, or audio and visual technology, has raised concerns since the 1990s as to whether oral evidence could be adduced effectively. This experience has been substantially increased and refined with the conduct of fully-online hearings as part of the response to the pandemic. This article sets out a number of judicial views on this issue. The article then takes the novel step of considering the assessment of oral evidence online through research findings from the psychology literature, including by way of the conduct of experiments.

Pre-pandemic views

Prior to the pandemic, court opinion was divided as to the use of AVL. One stream of authorities took the view that given the advanced state of AVL technology and because of the savings in time and cost, a substantial case needed to be made out to warrant the Court declining to make an order for evidence to be taken by AVL. Another number of equally authoritative judgments stated that the presumption should be that oral examination should be given in the normal manner, live and in court.

In Campaign Master (UK) Ltd v Forty Two International Pty Ltd (No 3) [2009] FCA 1306 the competing lines of authority were summarised by Buchanan J. His Honour was dealing with an application for AVL to be used to allow a witness to testify from London so as to avoid cost and inconvenience. The application was dismissed. Buchanan J was ‘particularly troubled by the prospect (or possibility) that the cross-examination of an important witness might be rendered less effective by the limitations of video link technology or the absence of the witness from the courtroom’. A key benefit for in person testimony was explained (at [78]) as:

‘It provides the Court with a more satisfactory environment in which to assess the nature, quality and reliability of responses by a witness, both to questions and to the overall situation presented by the necessity to give evidence in court. To my mind there remains, even in the modern context, a certain “chemistry” in oral interchanges in a courtroom, whether between a judge and counsel (or other representative) or between cross-examiner and witness. I would not wish too lightly to deprive a cross-examiner of that traditional forensic element…’

The main concerns raised in the case law were technical difficulties (e.g. delay or freezing in voice or picture transmission), the Court being unable to observe the witness and their demeanour, including being able to assess credit or overall credibility of a witness, and the fairness to the opposite party in the manner in which the trial will be conducted such as impinging on the effectiveness of cross-examination in elucidating the truth.

The pandemic and new technology

The COVID-19 pandemic and the ensuing mandated health protections saw courts turn to their pre-existing AVL, but also newer and more accessible communications technology such as Microsoft Teams and Zoom, as a means to be able to continue to function.

A key concern raised for hearings seeking to use AVL, or as part of adjournment applications, was whether the effective examination of witnesses was possible. Two of the key early decisions were Capic v Ford Motor Company of Australia Limited (Adjournment) [2020] FCA 486 (‘Ford’) and Australian Securities and Investments Commission v GetSwift Limited [2020] FCA 504 (‘GetSwift’).

In Ford, the respondent submitted that the cross-examination of witnesses over AVL was unacceptable. Perram J disagreed and observed that the earlier judicial statements voicing concern about cross examination were not made in the context of a pandemic causing the physical closing of courtrooms, nor were they made with the benefit of seeing cross-examination on platforms such as Microsoft Teams or Zoom. His Honour further stated: ‘[m]y impression of those platforms has been that I am staring at the witness from about one metre away and my perception of the witness’ facial expressions is much greater than it is in Court’ (at [19]). A similar sentiment was expressed by Lee J in the GetSwift litigation:

‘To the extent that demeanour does play an important role in assessing the evidence of witnesses, then my experience, particularly in the recent trial that I conducted, is that there is no diminution in being able to assess the difficulty witnesses were experiencing in answering questions, or their hesitations and idiosyncratic reactions when being confronted with questions or documents. Indeed, I would go further and say that at least in some respects, it was somewhat easier to observe a witness closely through the use of the technology than from a sometimes partly obscured and (in the Court in which I am currently sitting) distant witness box.’ (at [33])

Other judges have expressed a similar view that such assessments can be made as well by remote means as by traditional in-court examination: see, for example, Tetley v Goldmate Group Pty Ltd [2020] FCA 913 (at [16]) (Bromwich J) and Auken Animal Husbandry Pty Ltd v 3RD Solution Investment Pty Ltd [2020] FCA 1153 (at [49]) (Stewart J).

These decisions may be contrasted with David Quince v Annabelle Quince [2020] NSWSC 326 which concerned allegations that transfers of shares purportedly executed by the plaintiff were forgeries and that the defendant implemented or procured that fraud. Counsel for the plaintiff submitted that ‘the first defendant’s demeanour in answering these allegations will be crucial in assessing her credit, and in properly assessing her denials’ (at [7]). Sackar J agreed and adjourned the hearing.

In Rooney v AGL Energy Limited (No 2) [2020] FCA 942, Snaden J noted that the matter before him would turn largely upon contested questions of fact and the court’s assessment of the key witnesses who are called to give evidence would be paramount. His Honour also pointed out while the AVL was generally reliable, ‘it is not uncommon for connections to be momentarily of poor quality, occasionally to the point that they are unusable’ (at [18]).

When the AVL clearly fails an online hearing cannot continue. But what happens if there is a degradation in quality of the audio or video? How does that impact the evaluation of the evidence? A growing body of psychological research suggests some answers.

Evaluating witnesses and managing sources of bias in remote communications

When we evaluate a speaker, we attend to what they say, but we also attend to how easy or difficult it feels to process the information they are sharing. That is, we have a sense of how much cognitive effort we are exerting to listen to and understand information we encounter.

Attending to content makes sense—it allows us to examine whether what someone says is logical, coherent, and lines up with other information we already know. This kind of analysis may help us to assess the credibility and veracity of a message.

Attending to the ease of processing a message however, can bias our judgements. In general, in cognitive and social psychology we find that when a message feels easy to process we tend to believe it more. That experience of easy processing can arise from potentially diagnostic factors such as consistency between people’s accounts, making feelings of easy processing, at times, a valid cue to truth. But many non-diagnostic variables can shape how easy it is to process information1, having systematic effects on the way we evaluate others and leading our judgements awry.

For instance, when information is perceptually degraded or linguistically difficult to process we evaluate that information more negatively: when we read information in low colour contrast font, we believe it less2 and when we encounter hard to pronounce names we evaluate the bearer of that name more negatively.3 In the context of the online court, our research4 shows that when it is difficult to listen to a message—there is background noise, or a bad microphone with a slight echo—it leads us to judge the person speaking as less credible, less trustworthy, and less accurate. This is not an effect that is limited to one cohort of speakers. Indeed, our experiments show that both child and adult witnesses with poor audio quality suffer from these more negative evaluations. We also know that scientists find the same fate. Professors talking about their work5 with more background noise seem relatively less competent and their research lower quality, even when we tell people about their credentials, having implications for expert testimony. What’s more, people’s memory for testimony is worse when there is background audio distraction and emerging evidence suggests that mock jurors tend to weigh testimony with poor audio quality less heavily in their final assessments of guilt.

These audio effects do not occur with significant dropout and long pauses, but with more insidious ongoing background noise—echoes, general static or traffic. Of course, these experimental findings have implications for the online court, but they also extend to physical courtroom spaces with poor quality acoustics. One might expect that warning people about the potential biasing effects of poor audio quality could mitigate its impact on human judgement, but research in cognitive psychology shows that people often find it difficult to track these biases and appropriately adjust their final decisions.

While the focus here has been on the effects of poor audio quality, similar effects have been observed for combined audio-visual disruption too.6 Resolving such issues may be as simple as monitoring audio quality during testimony and intervening when there is mild audio disruption. But some witnesses may not have the connectivity and technology to facilitate high quality remote communications. Therefore, increasing access and investment to improve these hearings, whether remote or in a physical space with poor acoustics, may facilitate communication, reduce cognitive effort, and support equity.

The courts (and lawyers) are able to use AVL for hearings, including witness examination, but knowing that audio-visual disruptions can affect the perception of witnesses must take steps to ensure that AVL is high quality. If the AVL degrades then a judge may seek to overcome the biases and distortions discussed above, but that creates further concerns of over or under correction. If the AVL is unable to perform effectively then an adjournment may be needed to preserve procedural fairness but also public confidence in the justice system.


  1. Schwarz, N., & Newman, E. J. (2017). How does the gut know truth. Psychological Science Agenda, 31(8).
  2. Reber, R., & Schwarz, N. (1999). Effects of perceptual fluency on judgments of truth. Consciousness and cognition, 8(3), 338-342.
  3. Newman, E. J., Sanson, M., Miller, E. K., Quigley-McBride, A., Foster, J. L., Bernstein, D. M., & Garry, M. (2014). People with easier to pronounce names promote truthiness of claims. PloS one, 9(2), e88671
  4. Bild, E., Redman, A., Newman, E. J., Muir, B. R., Tait, D., & Schwarz, N. (in press). Sound and Credibility in the Virtual Court: Low Audio Quality Leads to Less Favourable Evaluations of Witnesses and Lower Weighting of Evidence. Law & Human Behavior
  5. Newman, E. J., & Schwarz, N. (2018). Good sound, good research: How audio quality influences perceptions of the research and researcher. Science Communication, 40(2), 246-257.
  6. Fiechter, J. L., Fealing, C., Gerrard, R., & Kornell, N. (2018). Audiovisual quality impacts assessments of job candidates in video interviews: Evidence for an AV quality bias. Cognitive research: principles and implications, 3(1), 1-5.

Legg, Michael
Professor Michael Legg is Director of the Future of Law and Innovation in the Profession (FLIP) Research Stream at the Faculty of Law & Justice, UNSW Sydney and Dr Eryn Newman is a Senior Lecturer in Cognitive Psychology in the Research School of Psychology at The Australian National University.