鉄道踏切用警報ベルの有効度

抄録

In order to establish the effect of the alarm-bell of the railway crossing, the authors measured the acoustical spectrum for the bell sounds by means of an analyzer, and the masking effect of street noises on the bell sounds in normal hearing persons.
The bell sounds have a peak of 20db at about 3500cps in the acoustical spectrum.
This peak could be hardly masked by street noises and heard by normal hearing persons from a distance of 70 to 80 meters.