My singing tea cup

In my recent trip to China, I bought a tea cup with a removable tea leaves well.   It can allow tea leaves to be soaked in hot water within the well, and the well can be lifted out when the tea is ready to drink.  This tea cup was supposed to have been made in China’s Yi Xing (宜興) and made of fine purple clay (紫沙).

I just realized an interesting phenomenon  with my tea cup.  After pouring hot boiled water into it, it started to sing in a low-volume, celestial-kind, high-pitched song!  Almost like a solar wind passing through kind of tune.

My first guess was that the porous clay could have created the sound with air trapped in it, but I didn’t see small bubbles lining the walls of the cup, and bubbles usually give a bubbling sound.  My second guess was that the air trapped in the porous clay was expanding and escaping from somewhere else, instead of bubbling, hence creating a sort of whistling tune.  What’s your guess?

I’m starting to love my tea cup. 🙂