Pedestrian pushbuttons shall incorporate a locator tone at the pushbutton. Locator tone volume measured at 36 inches
(915 mm) from the pushbutton shall be 2 dB minimum and 5 dB maximum above ambient noise level and shall be responsive to ambient noise level changes. The duration of the locator tone shall be 0.15 seconds
maximum and shall repeat at intervals of one second. The locator tone shall operate during the DON?T WALK and flashing DON?T WALK intervals only and shall be deactivated when the pedestrian signal system is not operative