Abstract
At the busy streets and crowded open areas in Tokyo, the commercial address by the loud speakers is one of the most violent noise sources. Noise survey of them was carried out concerning to (a) average level of the street noise raised by the speakers, (b) statistical distribution of peak level of speech and (c) service areas. As they are generally masked by the traffic noise, we classify the cases as follows: (1) speech level exceeds the traffic noise level, (2) speech level is much lower than the traffic noise level and (3) the former is comparable with the latter. These differences are caused by the electric power of the speaker, traffic noise level and also the distance from the source. In every case the intelligibility of the speech is as follows: in the case (1) it is excellent, in (2) poor and in (3) good, and it seems fairly intelligible though the speech level is 3 or 5 db lower than the average level of the traffic noise.
