I am new the forum and wanted to see if there is anyone who could let me understand how I can tell if a recording has been played with edited.
any help will be appreciated .
An example I feel I am getting a lot of duplicated words in recording which I believe may have been applied and cut.
If the audio has been badly edited, there may be clicks or other glitches at edit points.
If the audio has been well edited, there will be no glitches, so you will not be able to tell from just listening.
If the audio is in a lossless format such as WAV (NOT MP3), then you can copy a word (or words) that you suspect has been repeated through editing and compare it with the word that you suspect is a duplicate. If there is an exact match, then it has been edited. You can use the “Sample Data Export” tool to find the exact sample values - if there is an exact match, you will see the same sequence of numbers for both occurrences of the word. (see: http://manual.audacityteam.org/o/man/sample_data_export.html).
If the audio is in a lossy format, (such as MP3, MP4, AC3 etc), then there will be no exact matches. There are also numerous ways that the edits could be subtly altered so that there is no exact match.
If the audio has been edited by a skilled sound editor that specifically wants to hide the fact that it has been edited, then there is probably no way that you or I could establish with any certainty that it has been edited. An audio-forensic expert ‘may’ be able to tell (see: https://goo.gl/wb7lA8)
thank you for the response appreciate it,
the issue I am having is the responses we are seeing all seems the same but the wave format is slightly different can an agent duplicate a response then change the wave format so we cant identically match these.
Are there any “agents” in an educational establishment? If this anything to do with a court case, you will need to find and pay for a qualified audio forensics expert recognised by the courts.
EDIT In short, if you put the copied word in a new track, align it precisely with the original, do Effect > Invert on only the copy then play both, there will be silence if the copy is an exact copy. If you select both the original and the inverted copy and Tracks > Mix and Render, there will be a flat line if the copy is an exact copy.
this isn’t involved in a court case or anything like that, I wanted to become more knowledgeable about the subject in question to help me with my current projects.
See the EDIT in my post above.
Yes. As I wrote previously:
“There are also numerous ways that the edits could be subtly altered so that there is no exact match.”