Presentation of research conducted by the World Blind Union and National Federation of the Blind in the United States to validate the effectiveness of the proposed minimum sound levels for quiet vehicles at 10 and 20 km/h. The researchers concluded that the proposed sounds levels do not add significantly to the detectability of an approaching vehicle by a blind pedestrian and that internal combustion engine vehicles were detected substantially sooner than quiet vehicles equipped with the proposed acoustic vehicle alerting system (AVAS).