I don't see how you can do that.
When I have done something similar, the original sound is turned off, and it never gets recorded.
So, there is nothing to recover.
..
I had burned the video of my nephew's birthday party on which we had inserted a background music years ago. I just want to know if there is a possibility to extract that audio and get the video/audio back to its original state where they we were shouting and screaming their lungs out
We cannot find the original tape.

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