rumbling water pipes

I have two toilets in my house.The flapper valves leak a little bit, and when they do, the water pipes in the house rumble for 15 or so seconds until the small amount of water is replaced. I am planning to replace the toilets with
6 liter flush ones, but until then the rumbling is driving me nuts.Any suggestions?

The fill valves are making the noise,your toilet replacement will fix that.
Or repair the ones that you have.