Buzzing fan noise at startup (video)

My 2010 Prius V just past the 24000km mark. I have a buzzing noise coming from the engine bay during startup. It happens when the interior fan is on. You can hear it clearly after you start the car, during the silence of the "boot up", before the ICE kicks in. I can't be sure if it continues to buzz after that because the sound of the ICE drowns it out. However, If I shut off the fan during the boot up, the buzz disappears. Finally, if I leave the fan off and start the car, there is no buzz.

During a recent oil change, a hybrid technician claims that this is normal. It used to happen infrequently but now it is consistent, so if it was normal, I should have heard it when the car was new.

Is there something wrong?

http://youtu.be/EyR9CVOUAUo