The Approaching Vehicle Audible System (AVAS) is an optional speaker setup in the front of the car that makes a humming sound equivalent to the volume of a standard petrol-powered vehicle.
Despite not yet being required by law in Japan, sales of AVAS will begin on August 30 for 12,600 yen ($170, excluding installation) for those who want their Prius to be heard.
The speaker is activated when the car starts up but can be turned off at the touch of a button if the driver so desires.
The synthesised electric motor sound is emitted at speeds up to 25km/h and rises and falls in pitch based on the vehicle’s speed. Toyota says it was designed to help pedestrians and other road users indicate the vehicle’s proximity and movement, aiming to “alert but not annoy”.
Toyota says it designed the system especially to meet new Japanese Ministry of Land, Infrastructure, Transport and Tourism guidelines for hybrid and other near-silent vehicles.
It is also planning to introduce other versions of the device for use in its petrol-electric hybrids, plug-in hybrids, electric vehicles and fuel-cell hybrids in the near future.
Other near-silent vehicles – including the Nissan Leaf and Chevrolet Volt to be released this year, and the Nissan Fuga hybrid and Fisker Karma due in 2011 – will all be available with synthesised sound systems for the benefit of other road users, pedestrians and the blind despite there currently being no specific regulations requiring their implementation.
Toyota Australia’s Mike Breen said the local arm had investigated the implementation of noisemakers for its hybrid vehicles and said there was still some work to do with ADR requirements.
“The TMC device will be used in Japanese vehicles to begin with ... There may be an opportunity in Australia, but we will continue to investigate,” Mr Breen said.
He referred to a report by the RACQ from earlier this month which found “hybrid vehicles pose no greater danger to pedestrians than equivalent petrol-powered cars”.
“The results showed that while hybrid vehicles could be nearly silent, modern conventional engines are quiet enough that pedestrians have just as much difficulty detecting them in situations where there is traffic noise,” the RACQ report found.
Results from the study found that 40 percent of participants failed to identify vehicles travelling at 60km/h in time to avoid a collision when relying solely on their hearing.
It concluded that “all pedestrians need to be aware of the potential risks modern vehicles of all types pose and take appropriate action to ensure their safety”.