It's a bit "kid-ish", but I've seen it work effectively at combating what you're talking about.
Have some kind of object that a person holds while they're talking. While the person is holding the object no one else is allowed to speak. Once they're finished speaking the object is passed to the next person and they get their turn (if they want).
The object can be anything, but when I've seen this strategy used it was a rubber ball a bit smaller than a soccer ball. Something big enough that everyone can see who is holding it, not something small enough to be hidden in a hand.
As long as the person running the meeting introduces the strategy well, and maintains its rules, it should work. You might get a little bit of backlash from people that think it's demeaning, but you'll probably find that they're the ones doing the interrupting.
The conch shell from Lord of the Flies. During weekly town halls we have a plush wireless microphone cube that we toss from the current speaker to the next.
Have some kind of object that a person holds while they're talking. While the person is holding the object no one else is allowed to speak. Once they're finished speaking the object is passed to the next person and they get their turn (if they want).
The object can be anything, but when I've seen this strategy used it was a rubber ball a bit smaller than a soccer ball. Something big enough that everyone can see who is holding it, not something small enough to be hidden in a hand.
As long as the person running the meeting introduces the strategy well, and maintains its rules, it should work. You might get a little bit of backlash from people that think it's demeaning, but you'll probably find that they're the ones doing the interrupting.