The community reaction to city noise was investigated by questionaires in Karatsu City.
1) The intensity of the community's reaction to street noise, classified according to type of district and width of road was: Commercial>industrial>residential district: and Two-lane road (over 10m)>one-lane road (5 to 10m)>alley (under 3m in width).
2) The intensity of annoyance reaction to street noise increased markedly when the noise level reached 60dB (A) or more during the daytime and 45dB (A) or more at night.
3) In order to sleep, one often tries to move one's bed to a room as far from a road as possible. This study shows, however, that this kind of easy defensive measure is not effective when the street noise level is raised to 60dB (A) or more by heavy traffic at night, given the present architecture of Japanese houses.