Whether you think they're needed or not, all electric and hybrid cars are going to be required to fit noisemakers so that they can't be missed at speeds of 15 mph or below.

To involve its fans, Ford posted four possible sounds for the noise that its upcoming 2012 Ford Focus Electric will emit as YouTube videos, linked to them on its Ford Electric Vehicle page on Facebook, and asked fans to comment.

As of this morning, Ford had received almost 400 comments (as well as more than 60 "Likes"). Almost 300 people have rated the candidates, as did more than 3,400 Ford employees in a separate poll.

All four of the proposed sounds are variations of electric-motor whirring, with a couple of them heading more toward a jet-engine whine.

Ford is testing the sounds, which it hopes will be "pleasing to customers," for both detectability (whether it can be heard) and recognizability (whether a listener understand that it means an electric car is near).

President Obama signed a law late last year that directed the National Highway Traffic Safety Administration to set standards for the mandatory, cannot-be-disabled, must-be-obtrusive noisemakers.

2012 Ford Focus Electric launch, New York City, January 2011

2012 Ford Focus Electric launch, New York City, January 2011

Final implementation is likely to be required for cars starting in model year 2014 or thereabouts.

The regulation largely resulted from political pressure exerted by the National Federation for the Blind, which maintains that quieter cars pose a hazard to blind people.

The legislation, however, doesn't address the noise a car emits; it requires noisemakers for specific powertrain technologies, so the laws are not likely to apply to a gasoline vehicle like a Rolls-Royce Phantom, not matter how quietly it "wafts" past onlookers.

If you're curious, the four sound candidates are embedded in the YouTube videos at the bottom of this post.

Test them out and tell us which you prefer (or whether you don't approve of this new regulation in the first place). You can also post your comments on Ford's Electric Vehicle Facebook page.

Leave us your thoughts in the Comments below.

Sound A:

Sound B:

Sound C:

Sound D: