Thanks Michael.

Well, for starters there's these two questions which have stumped me since I were a uni lad...:

1. Why does a kettle make a very loud noise, when a pan of boiling water doesn't?
2. Why is Britain 'Britain-shaped"?

The kettle body is resonating and amplifying the noise.:)
Does an old fashioned kettle that you use on the stove make a loud noise?
It does a bit, but it certainly isn't as loud as an electric kettle! And going back to the pan, the (slight) noise it does make isn't amplified when you put a lid on it!

I've experimented! :)
True, but you two are falling into the nifty trap! See, you're saying why something is what it is by saying its not something else; like saying a square is a square because its not a circle.

We need DEEP, ladies and gentlemen. Deep...! :D
And I still don't think the kettle one is answered yet either. Now can you see why these questions have haunted me for the last 20 odd years!?! ;)

We don't allow Google in the house on account of it not being house trained. But anyway, they didn't answer the question: lots of good stuff about why the kettle makes a noise, but nothing about why a pan (with lid on if you like!) doesnt. How often have you boiled water for your spaghetti and not realise its been on the stove boiling away for ages!? Not much noise you see...;)

I think its aliens.
Hmm, the pan on the stove will have a more uniform large area (the base) which is in contact with the water - the water heats more uniformly and you don't get superheating or cavitation - which makes the noise.

The kettle which often has a heating coil has a much smaller area and doesn't transfer the heat easily - hence the superheating and cavitation which is explained in the articles previously quoted.

You may find on some poor quality pans that don't distribute the heat well - especially on a low quality ceramic hob that doesn't heat evenly that you can hear some cavitation and see bubbles concentrated in a small area.
That's a good one - sounds very plausible. However, just to point out that my kettle is one which has a plate on the bottom and no physical element. So, essentially, my kettle and the pan on the stove are the same, aren't they?

Isn't this great? I think we need more questions for discussion. After all, this is probably what we would be talking about over a pint in the Hummy Arms, if there was such a place! :)
Try boiling the kettle with the lid off/open (if it has one) - it's a lot quieter as the sounds isn't as contained.

Also, even with a concealed element kettle, the heat won't be as evenly distributed on the base as many, certainly cheaper ones, just have a std kettle element soldered to the underside of the base.