| 摘要 |
PROBLEM TO BE SOLVED: To absorb sounds of a wide range of frequency regions by forming an acoustic material of a rubber material, providing the inside thereof with many random microcavities and utilizing these many random microcavities. SOLUTION: This acoustic material 1 is formed by adhering many small chip-like pieces 2 made of rubber in the state of having suitable cavities, so as to form random microcavities 3 and curing the rubber. The chip-like pieces 2 made of the rubber are sized, for example, 0.5 to 2 mm in diameter. The respective microcavities 3 are not fixed in their sizes and are different and random. The many small chip-like pieces 2 themselves forming the acoustic material 1 further form the small random microcavities in the inside, depending upon the process for production thereof. The many random microcavities 3 are formed in the acoustic material 1 in this way, and the many microcavities 3 varying in sizes absorb the sounds of different frequency regions, so that the absorption of the sounds of the wide range of the frequency region is made possible. |
