Interview roles and responsibilities
It is imperative that you walk into any customer interview with not only a clear idea of why you are conducting these interviews, but also a crystal clear understanding of everyone's responsibility in the customer VoC and what role they are going to play.
There are two key roles when conducting a customer interview. First is the role of the moderator. This individual "executes" the interviews. The second role is that of a "listener/note taker" whose responsibility is primarily to take good notes from the session. If you have the benefit of additional people in the interview (but please, not too many), they can act as "observers."