Questions about how 'voice' games work.

So, when I started tabletop I was on a very poor connection (And it was several years go) so I started entirely on text. You know, pose your action, pose exact dialogue, go into detail, try to describe everything from facial expression to tone of voice, you name it.  I got pretty used to that, but it seems to be more or less -dead- as a playstyle. So I've been considering jumping into voice. However, the one voice game I've been in was like being on a high-speed game show. (I admit it was partially my fault; I'm not a witty, fast-talking type naturally but I tried to play one.) Several times people asked me what I was going to say in response to something or what bluff I was to make, and after it taking me a few seconds I got a barrage of "Well? Well? C'mon!" Followed by "Screw it, you took too long, you missed." And that was when I tried to get a word in edgewise- it seemed mostly the game was about jumping in without any order or turns, but just shouting whenever you could. Is... that common for voice, or did I land a really sour one? How do you get 'in character' in voice? How do you describe action without it being practically empty?

One thing I have been asking my players is that they state the intentions of their actions first, then do their best to describe those actions.  This allows me as the DM to adjudicate accordingly or if there is a distinct chance of failure, request an appropriate character roll, regardless of how effectively the actions are described. Voice games are going to be faster paced than text games, however it also depends largely on the type of group that you have, as well as the GM and whether or not she/he can maintain good pace/control of the story.

Whether text or voice find a group that matches your own style, there's a lot of variety out there.  Some are loud and the player who talks over others gets to act, these are not my favorite, but some folks like them and they can certainly be boisterous and fast paced.  When I'm running a game even in non combat situations I usually go around the table asking each person if they want to act and giving them time, and that's the method I've often seen while playing as well.  If someone seems to want a moment to think things through I'll ask them if they want a moment to think about it and move onto the next person, coming back to them after that. 

Voice based games, especially one-shots, are often going to be much faster than a normal game. Although you might have ended up in a game with an incompetent GM and unfriendly players do not let this discourage you. What you described is not okay even for a voice based game, try and talk to the GM if they prefer to quicken up the session or if you will be given enough time to think.

While they of course are faster-paced, you seem to be describing an extreme here. Sometimes the loudest one DOES get the attention, but that shouldn't be the norm. In the games I played (and liked), it's usually that we let people finish their sentence, even if they are looking for the right words or are not as fluent with the language. People only get interrupted if it's appropriate (= it happens in-character, or there is an amazing joke to be had that depends on this context).  My advice would be to keep looking for a group that fits that style. I myself had big problems in the beginning, because I felt very awkward and shy talking with "strangers" over voice. But with time it got better, and this would not have been possible without the amazing people I met here on roll20.

I've watched a few of the twitch broadcasts from R20 here and they seem to be fairly representative of how voice games have worked in my experience. Maybe watch a few and see.