I think the large chunks of missing health are more than enough.
Honestly though, the sound fits perfectly at level 1. As cool as the idea is, making it louder as the game progresses would probably cause it to eat up too much of the audio budget -- meaning some abilities and other audio-reliant game functions and mechanics won't be able to work as intended -- especially given Q's low cooldown.
It'd be a repeat of Jax before they nerfed the sound on his ult. I remember being at a LCS game live and all you could hear was the massive booming "THWOMP THWOMP THWOMP!"