To stop noisy pipes when flushing the toilet, you can try adjusting the water pressure, insulating the pipes, or installing a water hammer arrestor.
By taking shorter showers and not flushing the toilet
it depends on how good the pluming is.
To prevent a flushing toilet from overflowing, you can quickly lift the lid off the tank and push down on the flapper valve to stop the flow of water. You can also turn off the water supply to the toilet by locating the shut-off valve near the base of the toilet and turning it clockwise.
Hire a plumber! or you could replace the seal inside
To adjust the toilet float and stop running water, locate the float mechanism inside the toilet tank. Adjust the float arm or screw to lower the water level. Test by flushing and adjusting until the water stops running.
The problem here is one of two problems, or both, depending on the installation of your toilet. One. The flushing rubber inside the toilet cystern on the bottom is now old and perishing and needs to be replaced. Two. Certain toilet cystern installations allow for the inlet over flow to flow into the pan of the toilet and not to the outside, thus causing the toilet to seem as though its constantly flushing, this also has a rubber inside of it and needs to be replaced. Check and make sure that the handle of the toilet is not sticky, it has been known that a sticky toilet handle (probably because the back nut is too tight) wont go down, therefore not allowing the flushing rubber to go back onto its seat to stop the water running into the pan.
There are temperature balanced shower bodies that will adjust the hot water flow when it senses that the cold water flow drops due to flushing the toilet.
either bend the arm of the float so it is partially submerged or adjust it with the screw that is attached to the float armature
either bend the arm of the float so it is partially submerged or adjust it with the screw that is attached to the float armature
Stop drinking for a couple of weeks and see if the flushing stops. If you can't stop drinking for that long, you have a much bigger problem than the flushing.
Increase your main line pipe size. When you have a small pipe installed, and while you showering the toilet is flushed it has to distribute the amount of water running in the pipes, resulting in the drop in pressure. Once you have increased the pipe size, you'll notice that the extra volume of water will accommodate for the extra water needed to fill the cystern while showering, therefore fixing the problem with a drop in pressure.
Sometimes the fill valve can vibrate while the tank is filling. Try removing the tank cover and flush the toilet, then check to see if you can stop the noise by pushing down or up on the float assembly. It may be as simple as adjusting the flow rate.