EVs too quiet for comfort

In a normal world, it is usually better to be quiet than to be noisy.

However, in a direct reversal of normal requirements controlling how rowdy a motor vehicle is allowed to be, cars in the future could – by law – be required to make more noise.

Indeed, new regulations slated for introduction in the US will require that normally stealthy conveyances such as electric vehicles (EVs) and hybrids are actually noisy.

Under these new regulations, which may be introduced in some shape or form in other countries, cars from the wild Rimac Concept S to the Telsa Model X, the Nissan LEAF to the Toyota Prius and even the upcoming Jaguar I-PACE would require external speakers retro fitted to improve their safety.

The new guidelines, developed in the US by the National Highway Traffic Safety Administration (NHTSA) and the Alliance of Automobile Manufacturers lobbying group, will require electrified vehicles to emit 47 to 50 decibels in a powered-on state when stationary and as much as 67 decibels when driving at speeds up to 30km/h.

According to the Alliance of Automobile Manufacturers, “We’re still reviewing this final rule. However we already know that it’s important that automakers have the flexibility to equip vehicles with sounds that are sufficiently detectable yet pleasant to hear.

"Consumer acceptance is critical and that hinges on sounds not annoying people inside the auto."

The new rules will require the emission of a noise range between 50 and 53 decibels when reversing, and between 53 and 56 decibels when driving forward at speeds up to 10km/h.

Up to 20km/h the noise output would increase to between 59 and 62 decibels to as much as 67 decibels at speeds up to 30km/h.

Got all that?

According to NHTSA Administrator Dr. Mark Rosekind, "This is a common-sense tool to help pedestrians – especially folks who are blind or have low vision – make their way safely."

Of course the next question concerns the quality of the sounds: It’s easy to make a noise as loud as you want, but loud noises are rarely pleasant.

Admittedly even 67 decibels is not excessive for a passing vehicle (a normal conversation is measured at typically between 50 and 60 decibels) but, as the Alliance of Automobile Manufacturers has recognised, due consideration will need to be given to ensuring the sounds are pleasant to the ear, not irritating.

Then again, that is in the ear of the beholder.

It’s unlikely that a lover of Vivaldi would find the staccato blast of an AMG Mercedes pleasant to listen to – and (by and large) vice versa.

Although the legislation is not yet accepted (and could be delayed by the installation of Donald Trump as president) it is expected that more than half of all new EVs and hybrids going on sale in the USA will need to comply by September 2018, with the rules becoming universal by September 2019.

Motorcycles and heavy-duty vehicles will be exempt.

The cost in the US of implementing the rules is estimated by the NHTSA to be around US$39 million a year and would involve the fitting of durable and reliable external speakers to produce the sounds. It is also estimated that this would be offset by the saving of between US$250 million and US$320 million a year in medical costs resulting from pedestrians being impacted by silent cars.

According to Mark A. Riccobono, who is president of the National Federation of the Blind in the USA, "This regulation will ensure that blind Americans can continue to travel safely and independently as we work, learn, shop, and engage in all facets of community life."

The Australian Department of Infrastructure, which is behind the drawing up of Australian Design Rules regulating vehicles on sale in this country, was approached for comment but gave no indications over the awareness of, or position on, the new US rules.