It is the most suitable mode for conferences, forums, meetings, training courses and live media events. Immediacy is the most valuable advantage, as the message is directly translated to the participants who do not understand the source language.
In a simultaneous interpreting, professionals normally work in pairs, since weariness can decrease the coherence in the interpreted speech. In this case, the work is done in a booth, which must be soundproof. They listen to the original message through headphones, interpreting it through a microphone so that the sound gets to the target audience.
Interpreters take turns every 20 or 30 minutes, so that one can rest and, at the same time, help the other colleague, looking for terminology, talking to technicians in case of sound problems…
Unless the event lasts less than 40 minutes, it is always advisable to have two interpreters sharing a booth.