Electric Car Sound Generators for Pedestrian Safety

Electric vehicles (EVs) have seen a rapid increase in popularity due to their environmental benefits and innovative technology. However, one concern that has emerged is the safety of pedestrians, as electric cars are much quieter than traditional internal combustion engine vehicles. To combat this problem, automakers and regulators have turned to electric car sound generators to alert pedestrians to the presence of these silent vehicles on the road.

These sound generators are installed in electric and hybrid vehicles to produce audible noise at low speeds, where the danger of pedestrian accidents is the highest. Various countries, including the United States, have implemented regulations requiring automakers to equip their EVs with such warning sounds, ultimately aiming to reduce the risk of accidents and improve overall pedestrian safety.

As technology advances, more sophisticated and effective sound generators are being designed and integrated into EVs, ensuring that the sounds produced are recognizable and match the needs of pedestrians and drivers alike.

Key Takeaways

  • Electric car sound generators address pedestrian safety concerns by emitting audible noises from quiet electric vehicles at low speeds.
  • Regulations in many countries require automakers to install sound generators in their EVs, prioritizing pedestrian safety.
  • Ongoing advancements in sound design and technology are improving the effectiveness of these sound generators and their integration with electric cars.
Electric car on a city street

Electric Car Sound Generators: Purpose and Need

Pedestrian Safety

Electric vehicles, including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs), are known for their silence at low speeds, which can increase the risk of accidents involving pedestrians and cyclists who may not hear the vehicle approaching. To address this safety concern, electric car sound generators have been developed to simulate engine noise and alert pedestrians to an approaching vehicle Electric vehicle warning sounds.

The pedestrians, especially those visually impaired, benefit from artificial sound generation as it helps them detect the presence of a car at low speeds. These sound generators emit noises up to 18.6 mph, as it is at this speed that tire and wind noise become audible, providing adequate warning to pedestrians US noise-making requirements.

Regulatory Compliance

Different countries and territories have adopted regulations to ensure that electric vehicles emit a certain level of noise to keep pedestrians and cyclists safe on the road. In the European Union, it is mandated that all new electric and hybrid vehicles are required to have an external sound generator for easy detection by pedestrians and cyclists since June 24, 2019 Silent electric cars must legally make a noise.

Similarly, in the United States, the National Highway Traffic Safety Administration (NHTSA) has determined that electric vehicles must emit audible alerts at speeds lower than 18.6 miles per hour starting from September 1, 2019 Electric cars must make noise after September 2019.

Types of Sound Generators

Electric car sound generators, also known as Acoustic Vehicle Alerting Systems (AVAS), are crucial for pedestrian safety. These systems provide detectable sounds for electric vehicles, alerting pedestrians to their presence, especially when the vehicles are traveling at low speeds. This section will focus on two common types of sound generators utilized in electric cars: synthetic sounds and realistic engine sounds.

Synthetic Sounds

Synthetic sounds are artificially generated audio signals that mimic a specific sound or create a unique sound signature for electric vehicles. These sounds are usually designed to be easily recognizable by pedestrians but not intrusive or loud. They can be customized according to the manufacturer’s preference, allowing the creation of distinct sounds for different electric car models. Some synthetic sounds may also mimic natural sounds, such as wind or ocean waves, providing additional auditory cues to identify the presence of an electric vehicle nearby. Researchers continue to test the effectiveness of various synthetic sounds to determine which are most easily detected by pedestrians.

Realistic Engine Sounds

Realistic engine sounds, on the other hand, aim to imitate the rumble of an internal combustion engine. These sounds are often generated using recordings or digital simulations of engine noises, providing a familiar auditory cue for pedestrians accustomed to hearing engine sounds from traditional vehicles. Some manufacturers might use a mix of synthetic and realistic engine sounds to create a unique acoustic signature for their electric vehicles. It is worth noting that regulations, like the Pedestrian Safety Enhancement Act, guide the development and implementation of these sound generators to ensure pedestrian safety.

In conclusion, electric car sound generators help to improve pedestrian safety by providing recognizable auditory cues for the presence of electric vehicles on the road. Both synthetic sounds and realistic engine sounds are widely used, depending on the manufacturer’s preference and the desired effect. With new regulations in place, electric car manufacturers continue to innovate and develop unique sound signatures for their vehicles, ensuring a safer environment for both pedestrians and drivers.

Electric Car Sound Compilation

Integration with Electric Vehicles

Hardware Components

Electric vehicle sound generators aim to improve pedestrian safety by alerting them to the presence of nearby electric vehicles, especially at low speeds. The main hardware components of these sound generators are usually an external speaker and a sound-generating module connected to the vehicle’s electrical system. The external speaker is typically mounted in the front and/or rear of the vehicle to project the alert sounds effectively 1.

Some systems may also incorporate microphones or sensors to monitor ambient noise levels. This enables the sound generator to adjust its volume accordingly, ensuring the alert sounds remain audible and effective in various traffic and environmental conditions 2.

Software Control

The software control aspect of electric vehicle sound generators involves programming the desired sounds and determining when they should be emitted. In many cases, the sound generators are designed to produce warning sounds when the vehicle is traveling at low speeds, usually under 18.6 mph, as lack of engine noise makes these vehicles harder to hear at such speeds 3.

The choice of alert sounds may be based on regulatory requirements, as well as the manufacturer’s branding or design preferences. Some electric vehicle makers opt for futuristic or unique sounds, while others choose more traditional engine-like noises. It’s worth noting that in the United States, there are federal regulations in place defining the required minimal audible distance for alert sounds at different speeds.

In addition to pre-programmed alert sounds, the software control may allow drivers to adjust the volume or choose from a menu of preset sounds, providing options for personalization. This software may also integrate with the vehicle’s systems to enable automatic activation of the sound generator when the vehicle is operating under specified conditions such as low speed, start-up, or reversing 4.


  1. https://techxplore.com/news/2021-11-adding-electric-vehicles-pedestrian-safety.html

  2. https://www.greencarreports.com/news/1129448_evs-and-hybrids-get-an-extension-to-meet-us-noise-making-requirements

  3. https://www.greencarreports.com/news/1129448_evs-and-hybrids-get-an-extension-to-meet-us-noise-making-requirements

  4. https://en.wikipedia.org/wiki/Electric_vehicle_warning_sounds

Effectiveness and Sound Design

Range and Audibility

Electric vehicle warning sounds are designed to alert pedestrians of the presence of electric vehicles (EVs) traveling at low speeds, as these vehicles can be significantly quieter than their internal combustion engine counterparts. Many governments have mandated the inclusion of artificial sounds in electric vehicles, given the potential safety concerns, particularly for the visually impaired 1.

Research has shown that adding sound to electric vehicles does improve pedestrian safety. Regulations require that EV sounds should be detectable at specific distances for various speeds. These tests have been conducted by acoustic researchers to ensure the effectiveness of electric vehicle warning sounds 2. One example of a system designed for this purpose is the Approaching Vehicle Sound for Pedestrians (VSP), which was developed for the 2011 Nissan Leaf EV. This system emits a digitally generated signal from an onboard speaker, providing auditory cues to pedestrians during low-speed forward movement and reverse 3.

Electric car engine

Avoiding Noise Pollution

While it is crucial to address pedestrian safety by adding sound to electric vehicles, it is also important to avoid increasing noise pollution within urban environments. The goal is to strike a balance between audibility and maintaining a pleasant soundscape. The “Quiet Car” standard, which requires all vehicles sold after February 2021 to emit sound when moving forward or backward over 20 mph, is an example of a regulation that considers this balance 4.

Audio engineers have been working on creating sounds that are not only effective at alerting pedestrians but also contribute positively to the overall soundscape. This involves giving careful consideration to the pitch, intensity, and frequency of the generated sounds5.

In conclusion, the combination of range and audibility, along with avoiding noise pollution, play crucial roles in the effectiveness and sound design of electric vehicle warning systems. These factors help to strike the right balance between pedestrian safety and maintaining a pleasant urban environment.


  1. Electric vehicle warning sounds – Wikipedia

  2. Adding sound to electric vehicles improves pedestrian safety – Acoustical Society of America

  3. Development of Approaching Vehicle Sound for Pedestrians (VSP) for… – SAE International

  4. A ‘sound design’: How hidden external speakers improve pedestrian safety – VehicleServicePros.com

  5. Adding sound to electric vehicles improves pedestrian safety – Tech Xplore

Future Developments

Innovative Technologies

As electric vehicles (EVs) continue to grow in popularity, the demand for improved sound generation technologies also rises. Researchers and automakers are constantly working on developing innovative approaches to enhance pedestrian safety. One example of these innovations includes the creation of customizable warning sounds that allow drivers to select from a range of preset noises. This not only aids in pedestrian safety but also provides a unique identity for electric vehicles.

Another promising development is the use of directional speakers that can emit sound specifically aimed at pedestrians or cyclists. This technology can potentially minimize the overall noise pollution while maintaining the required level of audible warnings.

Global Standards

To ensure the widespread implementation of sound generators in EVs, various governments and organizations are working towards establishing global standards. These standards specify the minimum and maximum sound levels, frequency range, and other crucial criteria that EVs must comply with to guarantee pedestrian safety.

The U.S. National Highway Traffic Safety Administration (NHTSA) has already issued a final ruling that requires 50% of “quiet” vehicles to have warning sounds by September 2019 and full compliance by September 2020. The ruling mandates that EVs emit sounds when traveling at speeds less than 18.6 mph (30 km/h). Similar regulations have been established in other countries, ensuring a harmonized approach to EV sound generation.

To sum up, future development goals in the realm of electric car sound generators for pedestrian safety revolve around the introduction of novel technologies, and the establishment and refinement of global standards. These advancements aim to offer both increased safety and a decrease in noise pollution while maintaining a pleasant driving experience for EV users.

Frequently Asked Questions

Are sound generators mandatory for electric vehicles?

Yes, sound generators are mandatory for electric vehicles. In the United States, the National Highway Traffic Safety Administration (NHTSA) has set a Quiet Car safety standard that requires all newly manufactured hybrid and electric vehicles to have audible alerts for pedestrian safety.

How does a pedestrian sounder work?

A pedestrian sounder is a device installed in electric vehicles that produces artificial sounds to alert pedestrians to the presence of electric vehicles when traveling at low speeds. These sounds are designed to mimic the noise created by traditional internal combustion engine vehicles, making them more easily detectable by pedestrians and cyclists. Electric vehicle warning sounds are emitted from speakers mounted on the exterior of the vehicle and are typically activated only when the vehicle is traveling at speeds below certain predetermined thresholds.

What is the purpose of an EV noise rule?

The purpose of the EV noise rule is to protect pedestrians, particularly those who are blind or visually impaired, from the potential dangers posed by “silent” electric vehicles. Due to the lack of engine noise, electric vehicles can be difficult to hear at low speeds, increasing the risk of accidents involving pedestrians. The EV noise rule aims to mitigate this risk by requiring electric vehicles to emit a detectable sound at low speeds, allowing pedestrians to be more aware of their surroundings and safely navigate shared roads.

Which electric cars have built-in sound generators?

Electric cars manufactured after the implementation of safety regulations requiring noise-makers typically have built-in sound generators. This includes most electric vehicles produced by automakers like Tesla, Nissan, Chevrolet, and others. As the rule mandates new electric and hybrid vehicles to have audible alerts, car buyers can expect any new electric vehicle they purchase to come equipped with a sound generator.

How does vehicle sound for pedestrians system affect safety?

A properly functioning vehicle sound for pedestrians system significantly improves pedestrian safety. Studies have shown that adding sound to electric vehicles can help reduce the number of accidents and injuries involving pedestrians. By making electric vehicles more detectable to pedestrians and cyclists at low speeds, these safety systems aim to prevent accidents caused by the quiet nature of electric vehicles. In the U.S., regulations require vehicle sounds to be detectable at certain distances for various speeds, and researchers have tested how well people detect electric vehicle sounds in terms of these requirements.

Can the noise level of an electric car sound generator be adjusted?

The noise level of an electric car sound generator is typically set to comply with regulatory standards and may not be user-adjustable. Manufacturers are responsible for ensuring that their electric vehicles meet the minimum requirements for detectable sound levels at various speeds established by regulatory agencies. However, some electric vehicles may offer customization options for the type of sound emitted by the sound generator, allowing the driver to choose between different sound profiles.

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