recreating echolocation

Expanding on John Wynne's Wireframe (audio drawing) idea, I could "shrink" the size of the space, or maybe an enemy's sound could get quicker as it bounces back?

It would use the same LBP model from the drum kit, but I don't know how to make it playable...maybe having an enemy coming at you. In the dark so you cant see and have to rely on audio.
I fix the drum kit dynamic, and make the main piston automatic. When the enemy comes closer to the player the frequency of the sound gets quicker, like echolocation. When it's close, avoid it by jumping. I would have to put the mechanic on the front most layer.

I also need to play around with the pitch of the sounds. You can't make a gradient of a sound effect (one sound going high to low, or changing the volume from high to low).
The change in the same sound effect's volume/pitch could indicate height of the player. Would not work for depth on the z axis. How do I make this playable?
Unfortunately the player can estimate his height from the camera view.
Why would player need to know his height, as opposed to simply guessing?

The sound effect from the point bubbles get higher the more you collect.


Also some birds use echolocation to navigate caves. :o

The level will be impossible to beat if the player cannot hear the audio.