High pitch frequency comming from the cpu

Question

HI AND THANKS FOR YOUR TIME,

THE CPU IS ETOWER 433I, WITH XP. THE POWER SUPPLY WAS REPLACED AND TEST OUT GOOD.

THE SOUND (HIGH PITCH-METTALIC), IS NOT COMMING FROM THE PSU, ANY FAN OR THE MONITOR, BUT APPEARS ALL OVER THE AREA....

ALSO, ATTEMPTS: CHANGES IN THE REFRESHING RATES, REMOVING DRIVES AND FANS FROM THE RUNNING CPU DOESN'T CHANGE OR ALTER THE SOUND.

THANKS FOR YOUR ASSISTANCE,

STEPHEN MICHAEL