It's not normal if they've been made/fixed properly. Could also be that in trying to get the wheel true they've left some spokes really loose and these are making the noise, also not good fixing. If that tension can't be evened out while making the wheel straight then it's probably knackered.
It’s pretty normal for a new or trued wheel to make a few pinging sounds on the first couple of rides. Worry about it if it goes out of true.
Aksium spokes are like iron girders and to get a wheel back from out of true some pretty high tensions might have been used I guess.