When mixing the tracks, we need to consider that they might (and probably have) started at different times. If we were to merge tracks without taking this into account, we would end up with synchronization issues. In our example, since Bob got in the room a good 20s (and that’s really a huge time for synchronization of audios), mixing both Alice’s and Bob’s audio tracks together would end up having one speaking over the other.
To make merging easier, the start time of all tracks from the same room is the creation of the room itself. Let’s get the start times for all the tracks from this room