In this short video from FIA Formula E, you can get a really good idea of what the electric race cars will sound like and their rapid maximum torque acceleration, even though this video shows a prototype for marketing and crowd pleasing purposes.
Gear changes can clearly be heard which are in interesting addition to the usual road going electric car which tends only to have one gear. Of course gears can still be beneficial, even to an electric motor since it may be too fast spinning to give grip so a reduction gear would be needed, but if it revs up too quickly again, changing gears will be required to get the cars top speed.
The on-board video was filmed in Moscow in February 2013.
Source; FIA Formula E