That was interesting. No doubt the manufactures might want to consider the sound of their bikes as many IC manufacturers are doing now, probably because it is easier to design sell a good sound than increasing the power of these bikes under current and future emission regulations.
I think I prefer the Zero as it has the quietest sound, followed by the Empulse. The other bikes are just too loud and high pitched for my taste. I found that loud high frequency sound, such as the Alta, Energica and Lightning have to be irritating when revved up.
