When the ticket instructions require speaker tracking, assign a number to each speaker as indicated (Interviewee 1, Interviewee 2, etc.). If no tracking is required, it is not necessary to distinguish speakers. Regardless of tracking, each speaker always goes on a separate line.
See: Speaker Identification (Tracking)
Example WITH tracking:
Interviewee 1: Can you repeat the question?
Interviewee 2: I didn't understand it either.
Interviewer: Sure, let's go over it again.
Example WITHOUT tracking:
Interviewee: Can you repeat the question?
Interviewee: I didn't understand it either.
Interviewer: Sure, let's go over it again.