Well not really say it like Hirano Aya, but rather, learn the techniques she used to be able to use such a range of vocals.
In this video, Hirano Aya appears on Shoko Nakagawa’s (Shokotan’s) Yumereji show. They then proceed with a seiyuu lottery and act out various anime voices.
Following that, Aya-chan gets asked about how she practices to get such a voice. She explains that since she loves reading manga, while reading it, she gives each character a different voice and proceeds from there.
The results are really crazy. Imagine practicing like Aya-chan and sooner or later you’ll be able to use a wider range of vocals ^^; I think it would also help in pronouncing better when using Japanese as well.
Speaking of which, for those who would like to practice their Japanese reading skills can check out ルルーシュの物語 . It’s a blog by a friend of mine who writes in Japanese. I probably should do some entries in Japanese as well ^^;