Gojo specifically called it a "sonic attack", which makes me believe it was intended to be powerful enough to actually function like an attack. Although it's possible that the attack wasn't strong enough to harm Gojo in the first place due to the power disparity, like I mentioned before, Sound doesn't really fit on the traditional AP system, as some sonic attacks in fiction are meant to just blow people's ears out, like Homelander's scream iirc. Obviously there are other examples like Black Canary's scream snapping people's necks with sheer force, or Majin Buu ripping spacetime, but I don't think Jogo's was meant to just hit people with the impact of the soundwave. If his intention was to blow out Gojo's ears, the fact that it didn't do that meant that Gojo likely suppressed it instinctually, as per his training