asked the Minister of Transport what further evidence he has obtained on amplification equipment as a warning device on priority vehicles such as ambulances; if he will extend the use of the siren now used on police or fire vehicles to ambulances; and if he will make a statement.

Experiments have shown that the effectiveness of an audible warning device depends largely upon its sound level, and that bells are more distinctive at a given level than other sounds. An amplified bell is likely, therefore, to be most satisfactory. Nevertheless, in order to meet the wishes of the ambulance authorities we have circulated for comment amending regulations which would permit the use of sirens on ambulances.