Multilingual voices

Hello there.
English is not my native language, so I'm using iPhone with Russian interface and voice. But often there is some English text for example in any not localized apps, song titles, descriptions, articles, et cetera. Vocaliser's Milena reads any English text really terrible.
Is there a way to have better sounding reading on both languages without switching it in the rotor every time when I meet English text?
Thanks in advanced.