Google sez this isn't a word, nor 'perturberance', and my dictionary agrees. 'Perturbation' seems to be the accepted form, yet it looks and sounds very odd to me, and I evidently picked 'perturburance' up somewhere.
What say you?
I know I'm 6 years late here, but I really wanted to contribute. Googling 'perturberance' is what got me here. I had this word in my head and was in the process of using it in a gushing sequence, the moment of which is now lost, likening a waterfall to sex. I really was certain that it was a word; it came so effortlessly and clearly into mind, having a very satisfying phonic fit for my eroticised metaphor. Disappointed that apparently the world at large doesn't share my romance with perturberance I relented. Oh woe.