When I accelerate moderately hard, I can hear a quiet wheezing/breathing noise. It sounds like someone breathing through a tube. Is this a vacuum leak? I can't hear it when idling, during slow acceleration or when cruising.

*Perhaps on a related note, I flushed my power steering fluid recently. The car was accidentally started with the reservoir inflow tube removed and I'm sure it started sucking air. We spent some extra time bleeding the system ala the FSM method. However, I hear it might cause some noises during higher speeds?

**Also, my AC makes the same noise (I think it's the freon evaporating through the tubes?). It does this on and off every 30 seconds. Not sure if this is related.
The AC system works though, an IR temp reader said 45 degrees on recirculate.