This is what happens when someone is ringing a bell "full circle". The clapper hits the side of the bell (known as the sound bow) after the bell has rotated about 300 degrees from the vertical - when either the sallie (the fluffy coloured bit on the rope), or the tail end of the rope, passes the ringer's face.
It usually takes from 1 to 2 seconds for a bell to rotate 360 degrees, depending on the size of the bell.