Some examples

Here are a few examples** from my experience of egregious transcription of indistinct covert recordings that have either misled or needlessly distracted the court. Please recall I see only a tiny fraction of cases involving indistinct covert recordings.

They’ll be dead by Tuesday

This was a murder trial, with overwhelming evidence against the accused. Prosecution sought to add to that overwhelming evidence by suggesting the above excerpt contained the words ‘They’ll be dead by Tuesday’.

As is often the case, the audio is of such poor quality it is difficult to say with confidence what was really said, but it is clearly not the alleged phrase. Demonstrating that effectively is a time-consuming business, but necessary to avoid the police version being given to ‘assist’ the jury – which, as demonstrated in detail elsewhere on this site, is liable to cause them to ‘hear’ the alleged phrase even though it is clearly not spoken.

Fortunately in this case, the judge was persuaded and the police version was not admitted, so the whole exercise was merely a distracting waste of time for both prosecution and defence.

As discussed in the Case Study and elsewhere, the outcome is not always so benign.

An interesting – if worrisome – judgment

This is another case with an indistinct covert recording and a police transcript. My report concluded that the words heard by police could not be verified from the acoustics.

However, the judge ruled that the police opinion was more reliable than mine – because the words ‘heard’ by police were backed up by independent information.

You can see why that would seem like a reasonable conclusion, but is it really valid?

If there is independent information about what was said in a particular recording, that is useful evidence – but it is quite different from actually hearing the words in the recording itself.

In this case, it was the independent information (not the acoustics alone) that caused the officer to hear particular words that fitted that independent information.

  1. To use the independent information as confirmation of the officer’s hearing is circular.
  2. To use the officer’s transcript as additional evidence (on top of the independent information) is double dipping, making the prosecution case seem stronger than it is.
  3. To then use the transcript as confirmation of the independent evidence adds yet more circularity – and deflects attention from critiquing the independent information. Since it is the independent information that is the source of all other ‘evidence’, a proper and thorough critique is essential.


The judge in this case made his ruling without asking any questions so he was unaware of this well-established knowledge from the field of phonetic science.

Even more unfortunately, his ruling now stands as a precedent that will encourage other judges to make similar rulings in cases that seem similar on the basis of common knowledge – even if the phonetic issues might be substantially different.

The important take-away

If the only way to hear particular words in a recording is to have knowledge of independent information (or to have a transcript prepared by someone who has that knowledge), then the recording is not adding new evidence to the case.

At best it is confirming the independent information, and even that is complicated by the problem of priming (i.e. listeners being liable to hear what they expect, even if acoustic information is lacking or contradictory).

To treat the recording as additional evidence is a form of ‘double dipping’, making a case appear far stronger than is really is – and deflecting attention from testing the reliability of the independent evidence.

In cases like this it is easy to be misled into feeling the independent information is confirmation of the transcript, forgetting that it was the independent information that caused the transcript to be made the way it was in the first place. A form of circular reasoning that can have disturbing consequences, as demonstrated by the case study.

All caused by false beliefs about the nature of speech and speech perception.

International examples

It is not only in Australia that things like this happen. You might be interested to explore a collection of international examples of mis-use of speech evidence usefully gathered together by European journalists.

** These examples have been simplified to make the crucial point clear, and in some cases slightly altered to protect anonymity.

Sign up here for occasional news about Forensic Transcription (no spam!)