The noise is most likely coming from the ballcock, ortherwise known as that “valve looking thing” inside your toilet that shuts the water off. There is a very simple test to determine is this is indeed the culprit. Take the lid off of the tank and flush the toilet. When that valve (ballcock) starts to make noise lift the float up. If the noise changes or stops then you might have determined the problem. To fix this problem you first need to shut off the water at the valve located under the toilet tank, on the wall (the angle stop). Once the water is turned off you should remove the top of your ballcock. Many newer models just turn to the left and lift off, some older models require a screwdriver. You will find a washer or rubber looking piece. Take this piece to Val’s (or your local plumber) and they should have a replacement washer. Note that some older models are very hard to find parts for and you may have to change the entire ballcock. Don’t dispare, it’s not hard. If you do need to change the entire unit, it’s only a few turns of a wrench under the toilet tank. For further information please email us.