@article{oai:jaxa.repo.nii.ac.jp:00034691,
 author = {五十嵐, 寿一 and 子安, 勝 and IGARASHI, JUICHI and KOYASU, MASARU},
 issue = {6},
 journal = {東京大學理工學研究所報告},
 month = {Mar},
 note = {Normal acoustic impedance of commercial materials, such as, tex, felt, rock-wool and glass-wool was measured by pressure-length resonance method. Detail of apparatus used was mentioned. Absorption coefficients for normally incident sound were calculated from the results. Coefficients of random incidence were also estimated by the formula derived from the normal impedance, which will be useful for the acoustical design of the room., 資料番号: SA2410173000},
 pages = {213--218},
 title = {音響材料の吸音率},
 volume = {7},
 year = {1954}
}