The flat below me and my flat have different toilet noise problems.

1) Flat below seems to make a loud fog horn noise throughout the filling of the tank after a flush. The noise travellers all the way through my flat.

2) My toilet has recently started making a fairly loud squeak for a split second at the very end of the filling of the tank. This only happens sometimes.

Can someone please recommend a course of action to resolve these two problems?

Many thanks

Sounds you have described are typical of bad fill valves(ballcocks.) That are inexpensive and easy to replace.

I agree completely with ma, replace both fill valves and you should be all set.