Cricket sound every 30 minutes

I have a coworker that always play practical jokes on folks. So to give him a taste of his own medicine I want to build a sound device that will play an audio file (cricket chirping) every 30 minutes and put it in his room so it chirps throughout the night. I have searched the net for an hour or so and found nothing.

Any items needed I'll have to order since I'm stationed in Pakistan and running down to the nearest electronic store isn't an option.