2007 Prius I can hear a squeak when in motion. Hard to pinpoint from where but seems possibly towards the upper-left. It comes and goes and I've heard it at many speeds, though mainly within 25-45 mph. It's an annoying little sound. Audio of the squeak can be heard in the background (while going ~30mph): prius noise.mp3 Took it to the dealer and they told me that they never heard the squeak when they took it out to test it (this was before I had the bright idea to record it). So what could it be?
I don't hear anything but road noise in your recording. Perhaps it is too high pitched to make it through the recording, which is probably limited to speech range frequencies. (My ears are good.) But just as a guess, it is one of the snap in pieces of the dash or pillars. Try pressing on all the plastic bits one at a time to see. My driver side windscreen pillar piece vibrates a bit.
Jenson: Sounds like the noise I HAD in my 2008. It's related to the ac/heater vent on the left side of the dash. It's that silver rectangular thing with the black round knob for controlling the air flow. Just grab ahold of that unit and pull straight toward you and it'll come out. When this happens, look at the arm that is connected to the black round knob I mentioned. The noise is from the connection of the arms/levers. I put very heavy silicone brake grease on this connection and noise has been gone for quite awhile now.