I just noticed a hiss sound coming from the bottom of the dash where the steering wheel is. Only happens when the ac is on. Almost sounds like something turns on them a few seconds later turns off. Has anyone had this issue before ?? Also made a video to help. Alittle hard to hear but you can hear it.
2008 under dash hiss noise:

 

Just tested with the ac off and the air / vent blower on and there was no noise. So the noise only happens when the ac is on. Still do not know why the noise is coming from underneath the steering wheel

 

BUMP!!! help

 

here is the video

 

My car makes the same noise.

 

any clue what it can be?? has to do with the AC compressor. also hear and interior noise was well while driving

 

i have a 2013 and my car does the same thing... maybe not as loud?
are you sure this isn't normal? nothing sounds abnormal to me in your video... just the a/c turning on and off

 

Same happens to my 2010 wrx. Only happens on the initial start of the ac. Then several seconds it goes away. Mayb your compresser just old. How many miles on your wrx

 

Has 90k on it.