Simultaneous interpreting is when an interpreter orally translates (i.e. interprets) the original speech into the target language while the speaker is speaking, pausing as little as possible.
Simultaneous interpreting is normally carried out in a booth, except when it is whispered or chuchotage,a kind of interpreting in which the interpreters accompany the person for whom they interpret the speech and whisper it in their ear in the target language. When interpreting in a booth, the interpreters only work on their own for an hour and a half or less, or with a partner when they have to interpret for longer. Since an interpreter’s work may become less fluid and the quality of the target discourse being delivered could be affected, interpreters must rest. Moreover, having two interpreters in the booth not only guarantees the quality of the interpreting service, but also allows the interpreting to go faster since there is real teamwork behind the resulting speech.
Cases where it is advisable to have a simultaneous interpreting service to ensure the audience understands what is being said include congresses, conferences, international meetings, some lectures, etc.