When I start my computer, and it warms up, it starts to make this high-frequency sound for about 5-10 minutes. My dad can't her it, but me and my mom can. It gives me some nasty migraines. It's not any of the fans in the PC, and it goes away usually in 2-3 minutes. It still hurts like hell though. I can hear it through the whole house.
Any possible explanations for this one guys?