“You hear that?” … “What?” … “Nothing.”
The dialogue presented contains a shining example of sloppy language.
Nothing is not heard. What is heard, what is perceived is silence. A condition, a circumstance is perceived. Else it could not be discussed or acknowledged in dialogue.
That which is perceived is, by definition, [part of] existence. Silence is perceived. Silence is something, not nothing. Furthermore the concept mentioned, the term nothing, is itself a thing.