The Toyota Prius has received a noisemaker option in Japan, to let pedestrians know that you’re approaching when you putter along in electric-only mode.

The silence of hybrids has long been one of the biggest issues for the cars, and Toyota, a big player in the market, just had to be the first automaker to put a solution into production.

The system places a speaker in the bumper of the Prius, which emits an eerie “spaceship” noise when you’re driving solely on the electric motor at speeds up to 25 kph. It was designed to comply with Japan’s Ministry of Land, Infrastructure, Transport and Tourism guidelines for hybrid and other near-silent vehicles.

The option will cost 12,600 yen (About $150 USD) and its use will be voluntary, as you can turn it off with the touch a button. Sales begin August 30th, and Toyota is considering bringing this option to the US in the future. You can see how it works in the video below, or read more about it in the press release.

Press Release

TMC to Sell Approaching Vehicle Audible System for ‘Prius’

Toyota City, Japan, August 24, 2010—Toyota Motor Corporation (TMC) announces that, in line with its efforts to ensure an ever-safer traffic environment, it will begin sales on August 30 of an onboard device designed to alert pedestrians and others audibly to the presence of a quiet vehicle, such as a gasoline-electric hybrid.  The device will be available nationwide through authorized Toyota dealers and Toyota genuine parts & accessories distributors for retrofitting on the third-generation “Prius” gasoline-electric hybrid vehicle.

The onboard device automatically emits a synthesized sound of an electric motor when the Prius is operating as an electric vehicle at speeds up to approximately 25 km/h.  The sound—aimed to alert but not annoy—rises and falls in pitch relative to the vehicle’s speed, thus helping indicate the vehicle’s proximity and movement.

The device is designed to meet new Ministry of Land, Infrastructure, Transport and Tourism guidelines* for hybrid and other near-silent vehicles.

TMC also plans other versions of the device for use in gasoline-electric hybrids, plug-in hybrids, electric vehicles as well as fuel-cell hybrid vehicles planned for launch.

Onboard approaching vehicle audible system details

Price	Compatible vehicle models	Function
12,600 yen (Includes consumption tax; does not include installation charge or other incidental fees)	Third-generation Prius	Emits a synthesized sound of an electric motor to alert pedestrians and others to the presence of a quiet vehicle.

*Issued in January 2010 and based on assessments from the Committee for the Consideration of Countermeasures Regarding Quiet Hybrid and Other Vehicles, in which TMC participated as a member of the Japan Automobile Manufacturers Association.  The committee began assessing possible countermeasures in July 2009, after hearing concerns of drivers and other people about gasoline-electric hybrids and electric vehicles operating in near silence.

Source: Prius Chat