Why do I want to *persuade* the other person that I'm listening? I might not be and therefore go down a road I don't find relevant to me. Honest signalling would allow the other person to course correct.
Even if the manufacturer just picked the cheapest possible dinging bell sound, that's also going to persuade you of something even if the manufacturer had no intention to persuade you. That would be passive, unintended persuasion, which we do constantly.
A microwave's tone could be chosen by the manufacturer to signify quality, true. However the primary meaning of the ding itself, to me is that it is signalling that my timer has run out and I might want to attend to it. Persuasion does not seem like the right word.