What’s AVAS? An Acoustic Vehicle Alerting System

AVAS (Acoustic Vehicle Alerting System), also called PWS (Pedestrian Warning System) are electric vehicle warning sounds that electric cars must incorporate by law. The main goal is to warn nearby pedestrians in order to minimize the risk of running over, since one of the main characteristics of electric vehicles until now is that they were completely silent.

Regulation establishes that AVAS must be a sound emitted by electric cars in Europe from the moment we start up to 20 km/h and in United States from the moment we start up to 30 km/h and, as a general rule, also when going back. Once these speeds are exceeded, system automatically switches off.

And this electric vehicles warning sound not only affects private vehicles, but must also include those intended for both passenger transport and freight transport.

How is that sound? What noise does AVAS make?

Until now, electric vehicles were completely silent, a feature that allowed reducing noise pollution, especially in towns and big cities, but now the law establishes quite the opposite.

That sound will have to exceed 56 decibels, which is equivalent to the level of a normal conversation, and should not exceed 75 decibels, which is equivalent to the normal noise of combustion vehicles. And in the case of frequency, we are talking about 1,600 Hz, which is specially designed for older people who tend to have most sensitive ears.

In addition, this sound is not equal throughout its journey, but varies depending on the acceleration and speed reached, and also varies depending on whether we start or go back.

We better find out how it sounds in reality, right?

This amazing promotional video about the minimalist BMW Vision M Next allows us listening to what its very creators baptize as “recreating the feeling of astonishment through sound”.

Goodbye to silent electric cars?

Although it is true that law requires plug-in vehicles to emit artificial noise until 20 or 30 km/h, we must not forget that electric vehicles are much noiseless than combustion vehicles.

So, affirming that electric cars will no longer be silent is not entirely true, since not only they will continue being so and will contribute reducing noise pollution characteristic of cities, but will also contribute improving road safety thanks to these acoustic alerts.

But why should electric cars make noise?

AVAS system for electric vehicles is basically designed to alert pedestrians, cyclists and/or nearby citizens who use personal mobility vehicles, and especially blind or visually impaired people who need a sound stimulus to notice and realize a vehicle is close.

Jaguar was one of the first brands to bet on creating its own acoustic warning, thought and designed especially for visually impaired people, as they relate in this video; as well as Audi with its e-tron, whose composer is committed to create something completely new; the sound of the future.

Does AVAS affect plug-in hybrid vehicles?

Yes, AVAS system for electric cars is also mandatory for hybrids, plug-in hybrids, and fuel cell cars, which, in turn, will emit a sound somewhat different.

The main purpose is to allow AVAS system to also distinguish which are the electric vehicles, which are the hybrids and what performance and/or speed they have according to the sound they emit.

We should also take into account that this system will be disconnected in hybrids when the heat engine turns on.

Electric cars will end up emitting a "noise"? Yes, but much more pleasing to our ears. Maybe new electric vehicles warning sound will be somewhat futuristic, maybe somewhat similar to Star Wars ships, but in any case, much less aggressive than the noise emitted by current combustion vehicles. Let's see a few examples!

• Mercedes EQC

In this video we can see the comparison about the Mercedes EQC model with another one of combustion of the same brand in Europe and another comparison in United States.

• Nissan IMx concept

As Nissan says, 'Canto' sound has been developed to improve pedestrian safety and ensure that when we hear it we say "there goes an electric Nissan!"

• Hyundai IONIQ Electric

As brand claims, they have developed "a sound like a spaceship."

Many manufacturers are already working on developing their own AVAS, like Porsche engineers, who want it to be "as emotional, sporty and powerful as possible within the framework of regulations."

When will AVAS be mandatory?

European regulations establish:

• From July 1, 2019: factory required for all new homologated models (electric, hybrid, plug-in hybrid, and fuel cell vehicles).

• From July 1, 2021: mandatory for all ecological cars and 0 emissions already existing (that is, new vehicles, but previously homologated and manufactured) that are sold, marketed or registered in Europe.

So Europe is following Japan and United States steps, which had already implemented measures for the electric, hybrid, plug-in hybrids and hydrogen cars to incorporate the AVAS system.

Japan already established guidelines in 2010 and United States requires full compliance in September 2020, but established that 50% of “silent” vehicles were required to incorporate AVAS by September 2019, the same date when China also implemented measures.