The type of balast does not only impact on electronics.
I know somebody with special needs kids (austic) and the school they attend had to change out the fixtures in the new additon that opened last September as the noise / EMI was affecing the whole class.
The teachers, GC site superintendent, and electrical contractor were the only ones who could not hear or feel what ever the ballast was putting out. The fixtures were swapped over a weekend and the classes behaviour change was noticable on Monday morning in the new wing.
