It's a problem that seems to become more intractable as every electric vehicle comes to the market - what noise should the cars make?
While adding extra noise to a car was almost unthinkable for automakers even just five years ago, designers are now getting to grips with the solution to a very modern problem caused by the near-silent running of new electric vehicles.
With no internal combustion engine to warn pedestrians, particularly children and the sight-impaired, of their approach there is a general consensus that some sort of artificial noise has to be emitted, at least for now, from electric vehicles.
Nissan opted for a Star Trek-style "whoosh" for its Leaf EV, and now Ford appears to be planning the same thing - and it's giving Facebook fans a chance to vote on the winner.
The US automaker, which intends to launch an all-electric version of its Ford Focus sedan later this year, has posted four YouTube videos for consumers to listen to, asking them to rank their favorites on a Facebook page.
Responses left so far have ranged from the enthusiastic "it really sounds like 'future'" to the less than impressed, with other fans saying "I vote for silent," "hope these sounds are some kind of joke" and "[sounds like] the mothership revving up right before it blasts off and leaves E.T. behind".
Ford says that it will keep fans updated on the process, sharing further information about the sound development in the future - a total of ten sounds are under consideration, according to the automaker.
Listen to the potential sounds for the electric Ford Focus:
See how Chevrolet researched the noise for its Volt: http://www.youtube.com/watch?v=_-v-pMxmHLE
Listen to the Nissan Leaf's noise: http://www.youtube.com/watch?v=3yO5msMEGZI