I love this game's concept! Using sound waves to bounce across the walls and manage a path towards the exit is a great idea! Though, while it may go against some of the ideas of the game, I believe adding in more visual guides to help players could be helpful. Sometimes the waves bounce around too fast in a way where from the player POV it can look like a confusing mess. Maybe when the waves bounce the wall has a slight light indicator on them?
Again, great game idea and I'd love to see something like this fleshed out!