Abstract
We have had occasions to measure sound levels of street-, vehicle-, traffic-, loudspeaker-, aeroplane-noise, etc. , in Osaka-area. Readings of sound level meter in the main street in Osaka City ranged 69. 5-84. 7 phons, being 74. 9 phons in average during day-time, and 69. 0-74. 9 phons and 72. 3 phons in the evening. Noise levels of vehicles, etc. were as follows: Street car ranged 80-97 phons, being 87. 8 phons in average; Omni-bus, 75-90 phons, average 83. 6 phons; whistle of vehicles, 60-105 phons, average 86. 5 phons. In the vicinity of the air-port, the noise level in a room was 80 phons in average (maximum 105 phons), when the aeroplane was flying over-head.
