Why does water make noise before it begins to boil?

Question

When you heat a pot of water to boiling, before there's any sign of bubbles, the water begins to make a sort of metallic hissing noise. What causes it?

Answer 1

Something makes a sound when it creates a momentary or periodic compression and decompression in the air.

Since the bubbles are moving up to the surface, air must move to make room for the bubbles popping, the moving air triggers the air next to it to move. Basically a chain reaction.

The traveling region of compressed and uncompressed air spread out from the around the source of the sound and spreads out at the speed of sound until your ear drum detects the pressure wave.

Note, the air is not moving that fast, the energy from the wave is rapidly.

Answer 2

boiling creates extreme heat
vapors (steam) causes upward pressure (heat rises)
this pressure forces its way through a noise making device
(steam through a whistle)
[as far as metallic hissing, that could be the metal lid starting to lift as steam begins to escape]
warning: water only makes noise as it approaches a boil
providing that you have a kettle or pot with a whistle

ex: if you use a regular pot and lid filled with water on a gas stove, and you leave the room unattended as water comes to a boil - the water could boil over, and put out the gas flame - leaving your gas stove pumping flammable (toxic) gas throughout your house

Answer 3

1. It's great ! Makes you want to read more . 2. You can't take a shower in a boiling water , so you may want to change it to something like " hot water" or "steamy shower" . You get the idea . 3. Love that you use a lot of verbs , it gives pace to a story even when your protagonist is just standing still ( or sleeping ) .

Answer 4

because it is already boiling just the bubbles are much smaller if you look close you will see

Answer 5

to get your attention