Sounds crazy, but why does my coffee cup buzz?

Question

this is the second time l've noticed it, i fill up a narrow ceramic mug with boiling water because i have tea in it, and there's no milk or sugar, and after l've filled it with boiling water it has a noticable humming/buzzing/ringing noise. it doesn't matter what surface the mug is on, it still buzzes. why does this happen?

Answer 1

its just like running your finger on the lips of a glass water half filled....however porcelain is densier

Answer 2

there may be a tiny pourous hole in it somewhere, after washing water will get into this tiny hole then when you pour the hot coffee in the water start to expand and sort of steam out of the hole one possibility, which will make a buzzing or hissing sound

Answer 3

It's all in your head m'dear.

Answer 4

Solution:

Coffee cup in one hand, vibrator in the other.

Answer 5

BECAUSE it is NON-ALCOHOLIC DRINK