New GM to two players, both with limited D&D experience (we're playing 5e). We're all well versed in written roleplay, but theater and acting doesn't come overly naturally to any of us. Add in the complication that we're located across the globe from one another (two on opposite ends of the USA, and one in England) and we've chosen because of our own comfort levels to do a voice-only D&D campaign, using Roll20. This means we do not use video in our calls, and are incredibly unlikely to do so going forward.
Our specific technology setup is that we hang out on my TeamSpeak server for the audio, and use Roll20 for the visuals and dice rolling.
Generally we're doing quite well with this system and having a great time, but one of its biggest flaws has quickly reared its head; it's a lot harder to roleplay, particularly with characters who are slow to speak, when you can't see the other person thinking/pausing/gesturing.
Everyone's giving it their absolute best shot and all credit to my players for reaching out to each other to clarify if they're thinking OOC or IC whenever there's too much of a pause, and leaving each other time to think, but I'm still concerned that our chosen style is cramping in-character interactions. One of my players is more quiet and slow to speak, and the other player accidentally runs over her or dominates conversations frequently. I would stress that this is not in any way a problem with that person; she's quick to stop herself if the quieter one tries to speak and is very respectful, it's just hard to leave that much dead air when you can't see what the other person is doing.
I'm looking to see if there are any tested methods for how I as a GM can facilitate and improve in-character roleplay in an audio-only environment. I'm not even sure this is a problem that can be solved; personal experience is welcome!
Please note that suggesting that we use video is not an option in this case; I am obviously aware of the hypothetical benefits but it is not a good fit for this group.