Well this is my sample, an old radio interview with co-star Satou Rina.
http://www.youtube.com/watch?v=ZEd_GSGXLkg
I'm not saying she goes around like exactly like Index, but given her more lively nature she definitely leans that way rather than Subaru's serious voice, unless you're referring to Subaru's more girlie moments then I can see where you're coming from.