How should I ask her out?

I work for a catering company for airlines, there is a girl name ashlynn who works for porter airline. never met her but she sounds really cute and other people tell me she is cute from my catering company when they go out. i am the dispatcher and we usually talk on the phone to get info on flights. She talks really soft when I talk to her and sorta tease her about it and tell her its cute. How would I go and ask her out without not even seeing her? Maybe to go ice skate or movie or is that too much not knowing her yet. How do I know she is interested. really hope to go out with her.