A tire noise reducing system comprises a pneumatic tire with a hollow, a wheel rim on which the tire is mounted so that said hollow forms a closed cavity, and a noise damper disposed in the closed cavity, wherein the noise damper is formed by fixing a strip of a porous material to the tire or wheel rim, the noise damper has a volume in a range of from 0.4 to 20% of the volume of the cavity, the noise damper has a sectional shape substantially constant in the tire circumferential direction, and the pneumatic tire comprises a tread portion provided with tread grooves defining a tread pattern having a sea ratio of 20 to 35%.