What is forensic audio transcription?

Forensic Audio Transcription

​A forensic transcript is a complete and accurate documentation of the words spoken in an evidence recording. These are completed to the best of our ability using high quality headphones and reference monitors. Ed Primeau has been practicing audio and video forensics for 34 years. He has a well trained ear and a deep understanding of audio equipment to better clarify and hear the events in a recording. The transcript most commonly ends with the following language:
'Based on the pains and penalties of perjury, I testify that the above forensic transcript is an accurate representation of the dialogue (or events) spoken during the time of this recording so help me' then we sign it.

As an audio forensic expert, I often create what’s called a forensic transcript. A forensic transcript is the scientific observation of words under controlled conditions, and a forensic transcript accompanies an audio enhancement. Audio enhancement is the process of removing unwanted sound and enhancing the wanted sound. Most often, it’s dialogue. If the audio enhancement is still difficult to hear, and that happens a lot, then the forensic transcript is an add on that is a scientific document that is signed and sworn by the expert witness as to the words that are spoken. In that document, I often use the word “unintelligible” because some of the time, you can’t make out what is being said and it’s best to air on the side of caution when that happens.

As a forensic expert, I have listened to thousands of audio recordings. I have enhanced them forensically using principles that are accepted in the scientific community. I have a very keen sense of hearing, and I call it critical listening. So as I listen to these recordings that have been enhanced, I can hear things that the normal person can’t hear. So the difference between a transcript and a forensic transcript is that the forensic transcript was created by an expert. Somebody who is an expert at understanding and deciphering dialogue. I am a neutral third party unbiased scientist. And it’s not just with critical listening. You actually have to zoom in and look at syllables and formants of words in a spectrogram which is a display of the sound.

Combined with critical listening and viewing the spectrogram, and measuring the syllables, and comparing the words that are in question in one part of the recording that may be repeated in another part of the recording. So now you have a known word over here and the sentence 3 minutes later that matches an unknown word here. It helps me to be able to conclude, beyond a reasonable degree of scientific certainty what’s being said. So I type it, and I transcribe it, and that’s what a forensic transcript is. And that’s another great thing about creating a forensic transcript if it was from a video. Now you can add the words to the screen and create a demonstrative exhibit from the forensic transcript in case the trier of fact will not let that in as a standalone piece of evidence. I have a case right now where we have that problem.

We’re concerned about the three pronged components to my work product. Began with a video, went to audio enhancement, was transcribed forensically in the lab, and then the words were put on the screen. So now we’ve got a demonstrative piece of video that has enhanced audio and the forensically transcribed and perceived words on the screen. That’s a very multipurpose piece of evidence based on a scientific foundation for the trier of fact. But the bottom line is this forensic transcript helps support the evidence in your case. Just because we can hear something in the lab, doesn’t mean it’s going to be easily reproduced to the trier of fact, opposing counsel, and the jury accurately.

Primeau Forensics often provides audio enhancement to help the court better understand the events as they occurred. To help in this process, we will also often complete a transcript so that the judge and jury can follow along to the evidence as it is played in court. This additional work product can be extremely useful in poor listening environments where not all parties can clearly hear the recording during playback. Primeau Forensics understands the importance our work products may have in the courts. High quality equipment is used for every transcript and each finished transcript is reviewed by multiple examiners in our firm.


If you have a video that you question or need help understanding, please give me a call for a pro bono conversation. I apply my forensic expertise to cases in the United States and many countries around the globe. Any and all formats of audio and video accepted. Retainer agreement available on request; travel expenses will be quoted in advance excluding meal expenses and flat rate time for travel instead of hourly.
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Call 800-647-4281 in the USA or +01-248-853-4091 Internationally.
Ed Primeau's Curriculum Vitae has several references which include cases he has testified in as well as clients he has worked for in these cases.