In my Quest to Understand Why the Hell Someone Would Propose Regulations as Stupid as the NHTSA Minimum Sound Requirements for EVs, I found NoiseOFF. NoiseOFF is a coalition fighting noise pollution. Here they post a very informative page on the whys and wherefores of this proposal: NoiseOFF Electric Vehicles
The salient points:
The National Federation of the Blind (NFB), an advocacy organization for its sight-impaired members is lobbying the government to mandate artificial vehicle sound on EVs. They are also collaborating with automakers to voluntarily introduce artificial vehicle sound. They claim that EVs pose a safety risk for sight-impaired pedestrians who rely on hearing an approaching vehicle to judge its speed and proximity while navigating intersection crosswalks and other traffic situations.
In 2007, the NFB provided seed money to a start-up company called Enhanced Vehicle Acoustics to design external loudspeakers on EVs. They have built prototypes for use on the Toyota Prius with the intention of licensing their technology to automakers.
In 2008, the University of California published a study that evaluated the effect of sounds emitted by EV and ICE vehicles traveling at five miles per hour. Subjects claimed they could detect the sound of an internal-combustion vehicle when it was twenty-eight feet away, but could not detect the sound of a hybrid vehicle (in battery mode) until it was seven feet away. The study was funded by the NFB.
In 2008, the NFB lobbied the National Highway Traffic Safety Administration (NHTSA) to hold a public hearing on the issue and called in government policymakers, automotive industry representatives and blind-advocates to testify. Representatives from NFB testifed calling for additional studies and legislation mandating artificial vehicle sound on EVs.
In 2008 and 2009, the NFB lobbied the United States Congress to enact what is now called the Pedestrian Safety Enhancement Act of 2009. The bill is sponsored by Senator John Kerry (D-MA) and Arlen Spector (D-MA). It would direct the Secretary of Transportation to study and establish a motor vehicle safety standard that provides for a means of alerting blind and other pedestrians of motor vehicle operation.
In 2009, the National Highway Traffic Safety Administration (NHTSA) released a technical report titled, ‘Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles’ (DOT HS 811 204) comparing the incidence rates of pedestrian and bicyclist crashes that involved EVs and ICEs under similar circumstances.
A total of 77 pedestrians and 48 bicyclists involved in crashes with EVs were sampled (compared to 3578 pedestrians and 1862 bicyclists involved in crashed with ICE vehicles comparatively). Within the sample group, there was a statistical difference in cases where EVs have a higher incidence rate when backing up or making a turn at slow speeds. There was no difference when both types of vehicles were going straight. There was no mention whether any of these accidents were caused by extraneous circumstances, such as distracted drivers or pedestrians using mobile phones or listening to music.
NHTSA noted that the results of the study was not intended to make national estimates on the issue, because the results were based on a small sample size. That caution however, did not hinder NHTSA and NFB from touting the report as a watershed in the national media.
As NHTSA is oblivious to the public health issues of noise pollution, representation from noise control advocates are shut out of the dialog.