So men could pick a woman they want to talk through a phone with a changed voice
this way they could ask questions, and all that. That's pretty normal thing to do.
The first twist was that suddenly second voice was appearing out of nowhere making woman surprised and curious.
And later on in one of talks two men were asking questions one woman, but... her ex was silently listening to the conversation! 
The room was set in such way, so it was like a "incognito" talk.
