| 摘要 |
A soundproofing material 10 is applied to a vehicle hood panel 14 on the side facing the engine compartment. The soundproofing material 10 as a whole has a sheet-like form and includes a pulverized rubber layer 11 containing rubber grains of various kinds of material, various sizes and various shapes and covering layers 12 which cover the pulverized rubber layer 11. Noises are absorbed topically by a number of rubber grains within the soundproofing material 10 and by air gaps present between the rubber grains. While noise generating sources such as an engine, an induction system unit, transmissions and so on are housed in the engine compartment, noises ranging over a plurality of wavelength are generated by them yet are absorbed by the pulverized rubber layer 11, because the pulverized rubber layer 11 contains a mixture of rubber grains of various kinds, various sizes and various shapes, and the frequency level of the noise to be absorbed by each rubber grain is different piece by piece.
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