Doesn't sound normal, but hard to diagnose without more info. How's your MPG? Any symptoms beyond the noise? Was your HVAC system on at the time of the recording?
It sounds like an electric motor which is on constantly and has issues. So it could be the inverter pump going out. There is a connector that can be unplugged to do that, see the picture a few posts down in this thread: Need Help with 07 prius | PriusChat Unplug the connector while the car is completely off, restart, and see if the sound is gone.
