This is an unrelated and poor interpretation of the claim.

After re-reading and self-reflecting, I do not agree. The original claim is about defining certain actions as intrinsically not side-effectful (no sounds can themselves be dangerous), but actions having side-effects cannot be considered in isolation of the physical and social circumstances they are embedded in, which can require restricting an action.

I think my reply really adequately responds to the core intent of the original comment.

I’d also like to point out that your reply is not helpful. Merely gainsaying something is not useful or informative.

Bringing up opera singers breaking glass as an example of sound vibrations physically hurting people is just not useful in a conversation about freedom of speech because it’s a nitpicky convoluted example that is not a great thing to bring up when you’re trying to redefine the claim so that you could rebut it. (Note that I am specifically talking about the example you brought to to support your interpretation of the claim. I’m fine with your speculation that the claim literally meant something along the lines of “sticks and stones can break my bones” rather than “free speech has never had adverse consequences”. It just didn’t need your qualification. I do appreciate the self-reflection, though.)

I'd argue that the orignal sentence was using 'sounds' a bit symbolically, so the clearer interpretations would be closer to "there are no communications I can utter that are dangerous".

His point being about the critical thinking on the part of the listener, not about the physics of making actual sounds.

A communication costs energy to transmit. It cannot be decoupled from physical circumstance. But it’s beside the point. The communication is still embedded in a context of the situation it’s in.

If you utter a communication to an insane person, the side effect might be that you are stabbed. You as the person uttering it must take responsibility for what neurophysical response in the mind of the listener might result.

If you emit communications, there can be consequences which are causal. Not strictly the volitional responsibility of the listener.