Forensic Audio Authentication

Is your audio recording edited?

Forensic Audio Authentication is the process of investigating a recording to determine the authenticity of the events, and to verify the evidence integrity. Throughout the audio analysis process, we also determine if the recording is consistent with an original, unaltered recording.


As a business owner myself, I am aware of the effort it takes to assemble a team of employees that conduct their business as if it were their own, and take pride in how they represent your company to others. As an owner who feels has achieved that status myself, I immediately recognize it in others. I must say that this is not common in the workforce today. From the first contact with your company, through closeout, every one of your employees made this experience a pleasure and acted with the upmost professionalism.
Abc Def
Abc Def
20:32 03 Dec 18
Primeau Forensics is a professional, top-flight organization that knows how to access and deliver verifiable forensics information quickly, efficiently and productively. Don't let their cheerful, friendly attitude make you think they are not on top of their game--they are!
dan schulte
dan schulte
18:35 12 Dec 18
I received credentials from two technicians, then a third person ended up doing all the work and kept in touch with me by e-mail. I never saw any proof that the work was done and they told me they found nothing. They could not tell me what was making the noise or the lights. A waste of $750.00.
Teresa Galyon
Teresa Galyon
16:13 13 Dec 18
Excellent work. Primeau took a low light camera recording of vandalism at my home and converted the video to images that we used to identity the vandals. Additionally, Primeau was able to identify characteristics of the vandals car that were used for a positive identification. Services were efficient, timely, and professional
Todd Conte
Todd Conte
15:18 27 Aug 18
Ed and his team are great! I took in footage of my boyfriends dog being stolen and they were so willing to take every step possible to enhance the video to retrieve the information we needed. The resolution on our camera/video wasn't great (our fault, not theirs) and they were unable to get the information we needed BUT they guided me in the next steps to take. Thank you guys!!
Anita Tela
Anita Tela
12:47 23 Oct 17

Audio Forensic Expert performs extensive analyses of both the audio content and digital information to determine if a recording is consistent with an original or has been tampered with. Edward Primeau has been practicing audio and video forensics for over 30 years. He has specific training in the analysis of digital audio evidence as well as sound authentication. He has experience testifying in courts around the United States, Canada and internationally. To learn more about places we have worked, click here.

Electronic Measurement

audio authentication

After critical listening, the forensic expert must use electronic measurement to examine the audio evidence. This is done by noting the prominent frequencies in the voices or other sound source and the noise floor. The levels of the recording and of the different frequencies can be measured as well. Tools such as spectrograms, frequency analysis windows and level meters are very helpful for observing and collecting this information. The expert should note the frequency range of the overall recording, the voices or conversation and the noise floor or extraneous sounds in the recording.

If the frequency range of a voice suddenly becomes larger or smaller or shifts in frequency range, that can be a sign of an edit. Sudden, unexplained changes in the noise floor level as well as the sudden presence of another background noise can also be a sign of an edit. As I mentioned before, I have come across recordings in which I could hear two noise floors. This can often be measured and seen in a spectrogram and a frequency analysis panel.

wavesurfer-and-izotope

Analyzing Metadata in Digital Audio Evidence

When I first began working as an Audio Forensic Expert, most of my work was with analog audio evidence in the form of mini, micro and standard audio cassettes. I did have some cases where reel to reel tape was used. Today almost all recordings are done digitally, there is additional information that can be analyzed when performing an audio authentication. Digital audio recordings contain metadata which reveals information about how the recording was made and the type of equipment that created the recording. If third party software is identified in the metadata then that footprint is observed and reported indicating the name of the software. Third party software is often capable of performing edits.

When examining the digital information, it is necessary to create an exemplar recording to compare the metadata with the original. An exemplar is a recording that is made in conditions that are as close to the original recording as possible . The exemplar is made on the same kind of audio recorder and, if possible, the same environment. Using this exemplar, the forensic expert can compare the metadata and HEX information of the two files. If there are inconsistencies in the data, that can also be a sign of tampering.

Digital Evidence Integrity

Audio forensic expert understands the importance of evidence integrity. The investigations we perform include careful analysis of every aspect of an evidence file to guarantee an accurate investigation. We understand the weight our conclusions may have in a litigation and therefore give the utmost attention to detail for every investigation.

It is important that a forensic expert examine an original recording. If an original is not available, then the copy being analyzed must represent what we would expect to see from an original recording. In addition, pass inspection and not have undergone any tampering. If a piece of evidence is not authentic, it should not be used in court because it may be incomplete or altered to purport events that did not occur.

If you have an audio recording that you question or need help understanding, please give me a call for a pro bono conversation.

Click HERE to email your questions or

Call 800-647-4281 in the USA or +01-248-853-4091 Internationally.





sidebar map
sidebar video
forensic associations