This is the most common type of interpreting as it is used daily in EU institutions, at the UN and in other international organizations or in the private market. The interpreters sit in a «booth» and listen to speeches in one language through a pair of headphones. They interpret the speech by speaking into a microphone which transmits their voice to the headphones worn by the listeners in the audience.
Simultaneous interpretation requires a great deal of concentration by the interpreter, so during multi-language conferences, two interpreters work per «booth» or per target language, in a half-hour-on, half-hour-off rhythm. Therefore, if the conference languages are e.g. German, English and French, there will generally be six interpreters. Working hours: a maximum of 7 hours with a lunch break of at least one full hour.
Technical equipment and professional sound engineers are as important for the success of the conference as the interpreters themselves. Booths, microphones, headsets and loudspeakers must work properly, particularly as interpreters are not trained to cope with technical problems if these should arise during a meeting. A number of Swiss companies specialize in conference technology. Interpreters and technicians often get to know each other over time and thus function as a team.
Simultaneous interpreting can also be provided in a whispering mode, for 1 - 4 people, all of whom must position themselves close to the interpreter, who in this case does not work with a microphone or headsets. Another possibility is the bidule system, a kind of attaché case with one microphone for the interpreter and headsets for about 20 listeners, which can be sent by mail to the meeting organizer. The bidule system means no booths or technicians are necessary. The interpreters sit near the speaker and whisper simultaneously into a microphone which transmits their voices to the headphone worn by the listeners. This interpretation system may be used with small groups and for short meetings of a maximum of 3 hours; in this mode of interpreting, we too always work in a team of two.
If no built-in installation is available at a conference venue, the organizer may hire and install mobile booths. Today's technology allows clients to hold meetings with interpreters almost anywhere.