A sound-damping unit for a sprocket has a mounting foot for connection to a sprocket and an elastic body placed on the mounting foot that is suitable for cushioning a chain running onto the sprocket. The elastic body is provided with a protective cap or protective layer. A sprocket according to the invention includes a circular sprocket disc having a number of teeth and tooth gaps in the circumferential direction. The sprocket is equipped with at least one sound-damping unit that is configured to reduce the noise upon a chain running onto said sprocket. The sound-damping unit is at least one sound damping unit as above.