Abstract
Ten audible warning signals, selected by the police scientific development branch as alternatives to the current signal, were evaluated in the laboratory in comparison with the conventional signal as to their 'attention getting' effect. Forty-two subjects were required to detect signals of rising intensity against a background of in-car noise whilst also carrying out a tracking task. The main conclusion of the study is that a significant improvement over the conventional signal can be achieved. It is also recommended that any change in audible warning signals should be applied to all appropriate vehicles.(A)