Simultaneous interpreting is used for conferences with large audiences, where the interpreters must translate what the speaker is saying in real time, with a minimal delay known as décalage.
At least two interpreters per language are required, working in a soundproof booth positioned so that they can see the room: in turn, they hear the speaker’s voice in their headsets and translate, almost simultaneously, into a microphone. Audience members can listen to the translation in the language they prefer on their headsets.
Costs and the number of interpreters needed vary based on the linguistic requirements of the meeting, the hours worked and the subject. For each foreign language, the requirements are as follows: 1 interpreter only for a maximum of 1 hour, 2 interpreters for 1-7 hours, 3 for any longer times.
Also required are one or more booths with workstations for interpreters, microphones for the speakers and headsets for listeners. (Source: Assointerpreti)