My wife and I live in one of two semi-detached units.
Recently, when our neighbours flush the toilet, the refilling of the cistern produces a load noise of rushing water. The noise is so load that we have to crank up the volume of our TV for the two minutes or so it takes to refill the cistern!
Our neighbours assure us that they have not made any changes to their plumbing.
Any ideas/suggestions as to what causes the noise and how to eliminate it?