Electric Vehicles


Our use of the term Electric Vehicles (EVs) describes hybrid electric vehicles, plug-in hybrid electric vehicles, and all-electric vehicles.

The evolution of the EV is a promising automotive solution that reduces maintenance costs and a dependence on foreign oil. It also reduces exhaust and noise emissions.

Millions of people who live near busy roadways, thoroughfares, intersections and parking lots are exposed to vehicle noise at all hours. Because electric motors produce less sound than Internal Combustion Engines (ICEs) that require a tail pipe muffler to mitigate noise emissions, EVs improve the urban soundscape. Consumers are attracted to EVs because they are quieter vehicles.

Artificial Vehicle Sound (AVS) is intended as an audible alert to warn pedestrians to the presence of an EV and also as a customizable vehicle tone to promote a brand. The industry term, 'Electric Vehicle Warning Sounds' is a euphemism. AVS is unmitigated noise pollution.

Artificial Vehicle Sound

The technology to produce AVS consists of external loudspeakers and a controller device that imitates ICE noise or branded sound effects by automakers. It may be possible for consumers to add custom sounds or increase the volume by modifying the electronics on the vehicle.

Auto companies are developing custom sounds for its EVs that go beyond imitating the sound of a slow moving vehicle. AVS is being developed to convey a marketing message through sound effects. The vehicles use external loudspeakers which has the effect of keeping the passenger compartment quiet while the noise is heard outside.

Automakers recognize that the way mobile phone ringtones convey a brand, vehicles can also be added with distinct vehicle sounds to convey its own brand. Ringtones on mobile phones is an estimated billion dollar business. The marketing and revenue opportunities from AVS will come at the expense of residents captive to unwanted noise.

Fisker Karma Plug-In Hybrid

A set of loudspeakers embedded in the front of a Fisker Karma plug-in hybrid sportscar. A representative described the sound as a mix between a "Formula One car and a starship".


The National Federation of the Blind (NFB), an organization representing blind people, lobbied the United States government to mandate AVS on EVs. They claim EVs pose a safety risk for sight-impaired pedestrians who rely on hearing an approaching vehicle to judge its speed and proximity while navigating intersection crosswalks and other traffic situations.

When the NFB first announced that EVs presented a danger, the media attention was considerable; however, few questions were raised on the impact of increased urban noise pollution.

In 2007, the NFB funded a start-up company called Enhanced Vehicle Acoustics to design external loudspeakers on EVs. They built prototypes for use on the Toyota Prius with the intention of licensing their technology to automakers.

In 2008, the NFB funded a University of California study that evaluated the effect of sounds emitted by EV and ICE vehicles traveling at five miles per hour. Subjects claimed they could detect the sound of an internal-combustion vehicle when it was twenty-eight feet away, but could not detect the sound of a hybrid vehicle until it was seven feet away.

A controlled laboratory experiment is inherently different than the environment of city streets where the din of traffic often masks individual sounds of vehicles in motion. Most vehicles produce low frequency sound energy that is non-directional. The broader implication is that any type of vehicle, including motorcycles, scooters, mopeds, segways, and bicycles also present a danger to the blind.

In 2008, the NFB lobbied the National Highway Traffic Safety Administration (NHTSA) to hold a public hearing on the issue and called in government policymakers, automotive industry representatives and blind-advocates to testify.

The NFB lobbied the United States Congress to enact legislation which would direct the Secretary of Transportation to study and establish a motor vehicle safety standard that provide a means of alerting blind and other pedestrians of motor vehicle operation.

In 2009, NHTSA released a technical report titled, 'Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles' (DOT HS 811 204) comparing the incidence rates of pedestrian and bicyclist crashes that involved EVs and ICEs under similar circumstances.

A total of 77 pedestrians and 48 bicyclists involved in crashes with EVs were sampled (compared to 3578 pedestrians and 1862 bicyclists involved in crashes with ICE vehicles comparatively). Within the sample group, there was a statistical difference in cases where EVs have a higher incidence rate when backing up or making a turn at slow speeds. There was no difference when both types of vehicles were going straight. There was no mention whether any of these accidents were caused by extraneous circumstances, such as distracted drivers or pedestrians.

NHTSA noted that the results of the study were not intended to make national estimates on the issue, because the results were based on a small sample size. That did not hinder NHTSA and NFB from touting the report as a watershed in the national media.

In 2011, the Pedestrian Safety Enhancement Act was signed into law. The act does not mandate a specific speed for AVS but requires the DOT study and establish requirements for sound levels on EVs.

Not all NFB members supported its agenda. Many sight-impaired members recognize that additional noise does not make their lives safer.

There are differences in sound energy. For example, the Occupational Safety and Health Administration (OSHA) mandates the use of back-up alarms on trucks for safety. However, the intense piercing noise emitted from current back-up alarms is a noise hazard for workers and a nuisance for nearby residents. Improved back-up alarms emit a broadband sound (white sound) that dissipates over a discrete distance reducing noise pollution. OSHA never acted to mandate broadband sound in spite of repeated calls to do so. As NHTSA is not concerned with noise pollution, representation from noise control advocates are shut out of the dialog.

While the United States Congress recognized the deleterious effects of noise pollution, no federal agency is mandated with monitoring its health and environmental consequences, including the Environmental Protection Agency (EPA) where its Office of Noise Abatement and Control (ONAC) was defunded. As a result, there are no standards on AVS where public health is concerned.

NHTSA published a proposed rule that would require all EVs traveling at less than 18.6 miles per hour to emit AVS, automakers have full discretion on the sounds the vehicle makes. The rule goes into effect in 2014.

CNN Report - Boy Hit By Hybrid Car

The National Federation of the Blind generated placements in national news media by scaremongering the dangers of quiet hybrids.

Alternative Solutions

There are technologies that can alert blind pedestrians to EVs.

One solution is a receiver device sight-impaired persons can wear that will emit an audible sound when an EV is in close proximity. EVs equipped with a transmitter sends a signal to the device relative to its distance. It would produce a discreet alert to blind pedestrians and have no effect on increasing noise pollution.

This concept was rejected by the NFB in favor of external loudspeakers on all EV vehicles.


Why are automakers and technology companies so eager to develop AVS?

By aligning itself with NFB and voluntarily adding external noise to its vehicles, the auto industry hopes to avoid any additional government regulation. By hedging that the government may mandate AVS, automotive and technology companies see financial opportunities with patent licensing fees for AVS systems.

Some consumers have negative views EVs: small, underpowered, range limited, and boring. Instead of a vehicle that is simply quiet, automakers can sell noise as something futuristic and high-tech. The marketable 'look at me' message is part of the experience of buying a new car. AVS recreates the aggressive 'vroom vroom' quality some consumers want in a new car.

The Society of of Automotive Engineers (SAE) created a 'Safety and Human Factors Committee' for quantifying the sound levels emitted by EVs. The SAE had previously collaborated with the American Motorcyclist Association in creating a system for measuring sound on motorcycle exhaust systems, intended to obfuscate label match-up, a more effective system to curb motorcycle noise.

The irony is that the auto industry is infamous for resisting safety improvements, such as seat belts (invented in the 1880s and not implemented until the 1950s) and airbags (invented in the 1950s and not implemented until the 1980s). In the case of AVS, the industry is racing to develop a solution to a non-existent problem. More so, the industry is astroturfing the issue of pedestrian safety.

An aftermarket parts supplier, Sigma Automotive, sells aftermarket hot-rod exhaust systems for the Toyota Prius on the basis that exhaust noise improves safety. As the vehicle does not displace exhaust gases in battery mode, the logic of turning the Prius into a muscle car for safety is completely lost.

Plug-In America, an advocacy group that works to promote the widespread adaption of EVs does not support AVS. Their position on safety is that EVs are quiet, but not silent. At parking lot speeds, an EV will produce similar sounds as ICE vehicles because of various fans, pumps, and tire noise.

Tesla Motors, Volkswagen, and BMW have not yet installed AVS on their EVs.

General Motors

General Motors (GM) collaborated with NFB to add AVS, what they called "Safe Sound Alert". In 2010, the automaker introduced its "Pedestrian-Friendly Alert System" that is manually activated on its Chevrolet Volt. The vehicle uses the horn to emit warning chirps at pedestrians.

Incidentally, GM was the automaker that developed the EV1, the first mass-produced EV of the modern era. Amid accusations GM self-sabotaged the program to avoid government regulation requiring zero-emission vehicles on the market, the cars were subsequently repossessed from lease-holders and destroyed.

Ford Motor Company

Ford designed their own AVS for the Ford Focus Electric and then polled consumers on Facebook to pick their favorite sound. They have not yet implemented AVS on their EVs.


Hyundai has its own AVS called the "Virtual Engine Sound System" on its Sonata Hybrid. Following the Pedestrian Safety Enhancement Act and learning that NHTSA rules would not allow AVS to be driver selectable, Hyundai removed the switch from the first production vehicles.

Toyota Motor Company

Toyota introduced a "Vehicle Proximity Notification System" that emits a sound relative to the speed of the vehicle. Toyota consulted with NFB on its system.


Nissan also manufactures the Infiniti luxury brand. Their "Vehicle Sound for Pedestrians" uses a forward and reverse sound for its Nissan Leaf. In a move that angered the NFB, the AVS can be temporarily turned off by the driver on the 2011 Leaf, but in compliance with NHTSA regulations, new models of the Leaf does not include an off switch.

Nissan consulted with the NFB on the developments of its AVS, as well as a Hollywood sound design studio. Their sound engineers worked with film composers to create custom sounds that have been described as being reminiscent of the futuristic flying cars in the dystopian motion picture, Blade Runner.

Fisker Automotive

Fisker Automotive introduced its Fisker Karma plug-in hybrid sportscar in 2010. The vehicle uses external loudspeakers to emit its custom sound. They also consulted with a film-industry sound design studio to produce its sound.

Fisker declared bankruptcy in 2013 and was subsequently bought out by a Chinese auto-parts company.

Lotus Engineering / Harman International Industries

Lotus Engineering is a consultancy group of British sports carmaker, Lotus Cars. Harman Becker Automotive Systems is a division of Harman International Industries. These two companies have collaborated to develop AVS systems with the intention of marketing its technology to other automakers.

Their "HALOsonic Internal and External Electronic Sound Synthesis" generates engine sounds inside and outside the vehicle with driver-selectable sounds.

Lotus Cars and Harman International Industries created a hybrid demonstrator vehicle that simulates gasoline engine noise using loudspeakers rated at 300 watts each, louder than most car stereo systems. They call it a "Safe & Sound" vehicle.

Harley-Davidson Live-Wire Electric Motorcycle

As exhaust noise from motorcycle straight pipes is justified by riders as a means of reducing accidents, AVS is positioned as a safety feature. In this case, an electric motorcycle with the artificial sound of a fighter jet plane or a vacuum cleaner, whichever you prefer.