Electric Burners: Strange Sounds Explained

[JoAuSc]

Forgive me if this ends up not being a physics question, but I've noticed that when you turn on the burners (electric) they make a sound that almost sounds like they're stretching, but not a continuous sound, more like a series of closely spaced ticks. This sound seems to increase and decrease volume and frequency every so often. Does anyone know what I'm talking about, or what the cause of these sounds is?

 

[Cyrus]

It's just the metal parts expanding and contracting as they heat and cool. Your car engine makes those same sounds.

 

[Danger]

Although it's not as pronounced because of the smaller scale, you can hear the same thing from a toaster or space heater. Pretty much anything metallic that undergoes a serious temperature change, in fact.