Talkback (recording) explained

In sound recording, a talkback system is the intercom used in recording studios and production control rooms (PCRs) in television studios to enable personnel to communicate with people in the recording area or booth.^{[1] [2]} While the control room can hear the person in the booth over the studio microphones, the person in the booth hears the control room over a PA, monitor speaker, in their headphones or interruptible feedback (IFB) earpiece. Take numbers, reference data, and sometimes count-ins or remarks are also "stamped" onto recordings through talkback, similar to a clapperboard.^[3]

Notes and References

1. Book: Talbot Smith . Michael . Jackson . K. G. . Townsend . G. B. . TV & Video Engineer's Reference Book . 1991 . Elsevier . 978-1-4831-9375-5 . 46/6 . Sound Mixing and Control.
2. Book: Hingley . Andrew . Tozer . E. P. J. . Broadcast Engineer's Reference Book . 2004 . Taylor & Francis . 978-1-136-02417-7 . 614 . 2012 . 4.10 Sound Mixing and Control.
3. Book: Talbot-Smith . Michael . Audio Engineer's Reference Book . 1999 . Taylor & Francis . 978-1-136-11973-6 . 2·113 . Second . en . Acoustics and Acoustic Devices.