US EV drivers won't be able to choose vehicle safety alert sounds

National Highway Traffic Safety Administration denies proposal after public consultation

US regulators have sensibly ditched proposals to allow electric car manufacturers to offer a choice of sounds to warn pedestrians that the unusually quiet vehicles are approaching.

Electric vehicles produce less noise when compared to cars powered by combustion engines, a situation that is considered a safety risk.

The National Highway Traffic Safety Administration (NHTSA) considered suggestions that buyers be allowed to choose their car's "ringtone" in 2019, but this week walked back on it "because of a lack of supporting data."

"The agency has chosen not to adopt... a proposal which would have allowed manufactures of hybrid and electric vehicles (HEVs) to install a number of driver-selectable pedestrian alert sounds in each HEV they manufacture," the regulator's final rule said.

Federal Motor Vehicle Safety Standard No. 141 requires electric vehicles to produce a pedestrian alert sound when stationary, reversing, and in forward gear up to a speed of 30 km/h. Beyond this, the NHTSA does not deem a sound necessary due to noise produced by tires and airflow at higher speeds.

However, since the regulations surrounding electric vehicles are still in their infancy, there was some debate as to whether this low-speed sound should be standardized or user-selectable.

Two industry groups, the Alliance of Automobile Manufacturers and Global Automakers, pushed hard for user choice, claiming: "Satisfying our customers is a primary concern for OEMs. Since 'one size does not fit all' neither will one alert sound for a given make, model, trim level and model year satisfy all those consumers purchasing all these same vehicles."

Basically, they argued that without a choice of sounds, customers would be put off buying electric vehicles. The NHTSA noted, however, that the groups provided no supporting evidence for their assertions.

On the other side, a number of advocacy groups for the blind commented on the agency's notice of proposed rulemaking (NPRM) arguing for the choice of alert sounds to be narrow or standardized.

The American Council of the Blind, for instance, said: "A distinguishable and uniform sound is necessary to assist the blind community in quickly identifying hybrid or electric cars," adding that "sounds need to be recognizable as a vehicle, ideally that of a car engine," and that car owners should not be involved in their selection.

Likewise, The Seeing Eye argued: "For recognition purposes, it is important that all vehicles emit the same standardized sound regardless of manufacturer."

These stances would not just be of benefit to the visually impaired, but, well, everybody. We all expect to hear an engine or otherwise car-like noise as pedestrians negotiating traffic. While the vehicle industry groups were happy to have an unlimited amount of sounds to choose from, the NHTSA nipped the issue in the bud.

A similar concern led to 578,607 Teslas being "recalled" earlier this year because of a "Boombox" feature that could allow drivers to "play preset or custom sounds through the PWS [pedestrian warning system] external speaker when the vehicle is parked or in motion."

The NHTSA deemed this to interfere with a safety-critical system so Tesla was made to disable Boombox when the car is in motion via an over-the-air (OTA) update.

Over the pond, researchers from University College London's Person-Environment-Activity Research Laboratory (PEARL) have been working on a universal sound for the burgeoning electric rental scooter industry, which has seemingly left a number of UK towns and cities with an abandoned vehicle on every other street corner.

Wisely, the group took into account "the needs of individuals including those with sight loss, hearing loss and neurodiverse conditions" from the get-go.

While The Register playfully opened a poll on how they should sound, with "TIE Fighter engine" obviously winning, when it comes to chunks of metal moving at high speeds, we can probably all agree that standardization is the way to go for the sake of safety. ®