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The Problem

The increasing popularity of electric (EVs) and hybrid electric vehicles (HEVs) on roads worldwide has presented a novel problem. These vehicles are almost silent up to speeds of 20mph. The lack of audibility can present a danger to other road users and pedestrians; particularly those who are blind or partially sighted.

Accident data has shown that during certain low speed manoeuvres, an EV is more than twice as likely to be involved in an incident with a pedestrian than a car powered by a conventional gasoline or diesel engine.

Research by major automotive manufacturers, regulatory bodies and government groups have concluded that the best plan of action to alleviate the dangers of these ‘quiet vehicles’ is to implement External Sound Synthesis (ESS) systems. An ESS system emits an audible warning to indicate an approaching vehicle.