A noise damper disposed in a tire cavity formed by a pneumatic tire and wheel rim is disclosed. A noise damper designed to use with a wheel rim comprises an annular body disposed around a damper-mounting portion of the wheel rim, and the annular body is made of a spongy material having an inside diameter of from 0.9 to 1.10 times an outside diameter of the damper-mounting portion. A noise damper designed to use with a pneumatic tire comprises an annular body disposed in a tire hollow, and the annular body is made of a spongy material having an outside diameter of from 1.00 to 1.10 times the maximum inside diameter of the tire hollow.