You can tell how someone feels about a person by the way they talk about them, to them, etc. Most of the guys I work with are married. And I happen to overhear some of them talking to the wife.
One guy - he just talks to her. You can tell he's not talking to someone about work, but it just sounds like a close friend.
Another guy you can hear the love in his voice. He answers the phone, "Hi, baby." Sometimes I consider the term 'baby' as not all romantic but more just there... But the way he says it, you can tell he loves her.
It's interesting to tell the difference in the way people talk to each other. You can hear an edge of annoyance, or the effort in making their voice be polite. The fake honey so you'll stay on their good side. Or the blunt honesty.
I think it's fantastic being able to tell the different voices. I hope I can hear them when I'm talking to someone though, then I can tell how they truly feel and what's really going on.