By and large, automakers have spent much of the last century trying to make cars quieter and more comfortable. Noise from vehicles can be disruptive and just generally annoying, so it makes sense to minimise it where possible.

However, the noise from the average motor vehicle can serve a useful purpose. A running engine acts as an auditory warning to those nearby. This is particularly useful to help people avoid walking in front of moving vehicles, and is especially important for the visually impaired.

Electric vehicles, with their near-silent powertrains, have put this in jeopardy. Thus, from July 1st, 2019, the European Union will enforce regulations on the installation of noise-making devices on new electric and hybrid vehicles. They are referred to as the “Acoustic Vehicle Alert System”, and it’s been a hot area of development for some time now.

They’re making the cars louder now?

It might seem like a waste of effort and energy, but safety is a serious businses. Monash University reported in 2018 that 35% of vision impaired persons surveyed had experienced collisions or near-miss incidents with electric or hybrid vehicles. This promises to be a growing problem as the take-up of electric cars increases, so it’s no surprise that laws are coming in to effect to deal with the problem.

The European Union ratified its guidelines for Acoustic Vehicle Alerting Systems, or AVAS, way back in 2014, giving automakers plenty of time to comply with the directive. The intention is for electric and hybrid vehicles to emit artificially generated noise when travelling at low speeds, for the purpose of warning pedestrians and other vulnerable road users of the vehicle’s presence and activity.

While there is no strict specification of the sound to be made, the intention is that a vehicle should make a sound similar in nature to that of its gasoline-powered equivalent. This is in order to make the system intuitive for all road users. It would obviously be confusing and dangerous if large trucks sounded like small hatchbacks, and vice versa, so cars are considered by category and weight class.

The official requirements make for interesting reading. The sounds emitted are intended to vary in volume and pitch, depending on vehicle behaviour. There are minimum requirements, enforced by a test regime, to ensure the systems meet the spirit and the letter of the regulations. The minimum sound level is 56 dB(A) as measured in the test, and the AVAS must be active at speeds below 20km/h. Above that, road noise from the tyres is considered to be loud enough to warn pedestrians. The AVAS is also expected to make sound when the vehicle reverses. Sound must be continuous, and the maximum sound level is restricted to 75 dB(A) – around about the same as a toilet flushing, or an average gasoline-fueled car. Outside of this, and some specifications on mandatory minimum frequency sweeps with relation to speed, automakers have plenty of scope to personalise the sound to suit their brand.

What’s It Like, Then?

It’s not the first time automakers have intentionally made cars louder with synthesized sound; sports models have been doing it for a while now, much to the chagrin of diehard automotive purists. However, rather than directly replicating the sound of an internal combustion engine, car companies have employed crack teams to develop unique and compelling sounds to usher in the age of electrification.

As you’d expect, most have gone with a very science fiction, spaceship-like sound. Some have been working on the technology longer than others; there’s video of an early Audi e-tron project from way back in 2011, 3 years before the EU decided to enact the AVAS legislation. Nissan have had their Leaf on the road making sounds for almost that long, while Jaguar launched their system with their all-electric I-Pace. Most automakers have stuck to a fairly futuristic theme, while putting their own twist on the sound.

Electric trailblazers Tesla are yet to reveal the noise their vehicles will make after the July deadline, and Volkswagen are similarly playing their cards close to their chest.

We’d be surprised if they go with anything too outlandish. The fact that it has taken this long for regulations to come in is a testament to the inertia of goverments and big business interests. Still, it’s been a topic of some thought for a while now, given that electric vehicle noise was a key plot component of a mindblowing Kevin James film from 8 years ago. If the EU had moved quicker by about a decade, we could have avoided The Dilemma (2011) entirely.

Is It A Big Deal?

Fundamentally, it’s a useful technology to keep pedestrians safe, and as the technology is only active at low speed, it’s unlikely to bother anyone too much on a day-to-day basis. Unlike your straight-piped Fox body project car, your AVAS isn’t going to wake the neighbours or send the neighbourhood cats scrambling up a tree. With the legislation being largely done and dusted 5 years ago, and with the US set to enforce similar regulations in the next few years, it’s pretty much a closed matter. Expect there to be minor regional differences in requirements, similar to the variances in indicators and automotive lighting the world over. Overall though, the average punter will barely notice the technology – other than noting that these new whizz-bang cars do sound awful fancy, don’t they? Change, it is ever thus!