SOUND ABSORBER, SOUND ABSORBER GROUP, AND ACOUSTIC CHAMBER

摘要

PROBLEM TO BE SOLVED: To absorb a sound more efficiently than a sound absorber using only resonance in a sound absorber using resonance.;SOLUTION: In the sound absorber 1, loops of a sound pressure amplitude of a standing wave appear in a position of an end face 13 and in a position separated by λ/2 from the end face, in the first internal space 15, where λ represents a wavelength of an absorbing sound, and nodes of the sound pressure amplitude appear in a position of an opening end 11 and in a position separated by λ/4 from the end face 13. The loops of the sound pressure amplitude of the standing wave appear in a position of an end face 23, in a position separated by λ/2 from the end face 23, and in a position separated by λ from the end face 23, in the second internal space 25, and the nodes of the sound pressure amplitude appear in a position of an opening end 21, in a position separated by λ/4 from the end face 23, and in a position separated by 3λ/4 from the end face 23. A pressure difference is generated between the first internal space 15 and the second internal space 25, since a position of the end face 13 is shifted by λ/4 horizontal-directionally from a position of the end face 23, a vibration part 30 is oscillated thereby, and acoustic energy is consumed to absorb efficiently the sound.;COPYRIGHT: (C)2009,JPO&INPIT