| 摘要 |
PROBLEM TO BE SOLVED: To provide a sound absorbing wall improved in sound absorbing performance in a jarring low sound area of about 400 Hz or less in frequency while keeping the whole thickness including a rear air layer, thin. SOLUTION: This sound absorbing wall is provided with a perforated plate 1 of 25-70 mm in thickness having a plurality of through holes 1a at numerical aperture of 0.3-14%, and a shielding plate 3 installed on the rear face side through a rear air layer 4. The rear air layer 4 is divided in a plurality of closed sections of 4.0 m2 or less in area by partition plates 5a, 5b. The perforated plate 1 is preferably formed by boring the through holes 1a in a porous ceramic block with communicating pores. In this sound absorbing wall, a sound absorbing peak of 0.6 or more can be obtained in a low sound area of 100-400 Hz in frequency.
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