I personally think audio contains javana power and reading contains it too but to a lesser degree. (When you read you record it or “hear it” with your mind so soundwave related to javana power are revibrating in your mind anyway)
I have some theories about it but recording actually saves the wave-pattern of citta which is secured in sound. I think we could scientifically reconstruct part of this citta just to the sound but the problem is just a medium and needed Ariya insight and explanations which we are not aware of and not understand yet which I think may or may not be reproduced scientifically. If we could actually understand the mechanism behind it we could develop a technical process to trigger those things by the outside meaning but those are just theories, keep that in mind.
The thing is when Ariya is recorded there is javana citta in forms of waveforms and right meanings and understanding which opens up a mind of a person who hears and have conditions to revibrate with it so to speak.