|Now, let's be perfectly clear, here. People who think that a cpu chip, within itself, can generate audible sound need to go relearn some basic electronics.|
First, there is no AC of any frequency that is LOW enough, anywhere in a cpu interface, to cause sound in the audible range. The ONLY AC signals within a computer system that could be in the audible range are "in" the sound system, the serial data port, and the PSU and other power supply and voltage regulation components.
Additionally, there is no "equivalent" to something like a dynamic/ magnetic, or piezoelectric, or other electro-mechanical device of any kind to generate this kind of sound in the chip.
A cpu is comprized of thousands of equivalent descrete components, none of which individually consume enough power to even GENERATE sound, even if the frequency WAS in the audible range. If they did, they would self destruct from that much power
A good comparison, for example, is the basic old fashioned crystal oscillator, which IS THE VERY example of an electro-mechanical-piezo device. A crystal oscillator DOES in fact physically vibrate, and IN FACT if one was operated in the audible range, you could probably hear it. It is possible, if a crystal is operated with too much power to actually fracture the crystal by physical vibration--something that used to happen back in the days of vacuum tube oscillators.
However, again, virtually all crystal oscillators are operated ABOVE the audible range, which means "about" 20KHZ
There is NOTHING in a cpu of ANY where near the magnitude of this power.
Additionally, because just about EVERY modern cpu is strapped down very securely by the socket/cpu/heat sink sandwich, even IF the thing (chip) could or did vibrate, the entire package of this sandwich would tend to dampen any vibration.
Now, it is VERY possible that wherever the source of this vibration or noise is, it could very well be transferred through the motherboard material, and the CPU assembly, being a fairly large component, is acting as a diaphrapm or sounding board.
There is no way this happens, directly from a cpu chip, period. You need to look elsewhere.