東京都内加入者室内騒音スペクトルについて

抄録

We measured the room noise spectra at subscribers'telephone location in Tokyo with sound level meter and filters, and couldn't detect the difference for the kinds of profession (residences, offices, shops, and factories)in singnificant level 5%. We estimated the noise spectra of various profession, of which results approximately agreed with Hoth's data. We also measured the room noise levels, and its mean value was found to be 57. 4 phon.