A rapidly moving softball makes a sizzling sound. It is most easily heard when you are catching for someone.
What is causing this sound? The movement or the spinning?
I will honest with you here - I have no idea. I would say it is the friction of the ball with the air so i guess it is probably a combo of both spin and movement.
The sound is caused by the air flow over the stitches in the ball. You will always have a little bit of sound on any ball thrown or hit with a decent amount of speed, but obviously, the faster it is spinning, the more stitches that are being exposed to the airlfow.