Board Thread:Sonic News and Updates/@comment-2054358-20140310221503/@comment-477304-20160124004345

Because he's a child, boys have higher pitched voices than men, so it's harder for men to replicate a boy's voice. Women, on the other hand, find it easier to do do and are often used to play young boys. The other alternative is to cast actual children, but there are two problems with that; one, child actors aren't usually that good at acting and two, they go through puberty and need to be replaced (Tails actually went through several male VAs before he was voiced by a woman).