Hello I've seen videos on YouTube on straight talk using Verizon lte and there data speeds where like 16+ and I get only 5mbps. Even with full bars of 4gLTE ? When I do speed test I see it say 13 but Gos to 5mbps?

Hello !
I'm looking for a solution to pair two bluetooth headset (or one bluetooth headset and one wire headset) to the same phone and then being able to speak between the two headsets.
I would use it like an intercom, but without the need of two phones.
Does anyone knows if it is possible and if there is an app for this ?
Thanks in advance, king regards
Vince