Hello, I'm hoping someone can help me identify the source of this odd hissing noise. I've made a audio recording of it. The noise can be heard on the driver side below the dashboard. Noise is only heard when pressing on the gas and gets louder with the engine rpm.

Any thoughts? Is it normal?

Thanks!

https://www.dropbox.com/s/nfochrcbag...noise.m4a?dl=0

 

anyone?