For conferences or lectures where interpreters have to use cabins for simultaneous interpreting, 2 or more usually 3 simultaneous interpreters are required for each pair of language. Each simultaneous interpreter works for about 30 minutes at a time in his or her language task and then hands over to the other simultaneous interpreter or interpreters. The reason for this is that simultaneous interpreting requires deep concentration of the interpreter and after about 30 minutes, his or her mind may no longer keep up to that level of concentration. It is essential to use 2 or 3 simultaneous interpreters for accurate simultaneous interpreting.
Consecutive interpreting only requires one interpreter who can often interpret in three or more languages where necessary.
Although consecutive interpreters can often work in several technical or business fields, it is better to send some of your documentation in advance to help the interpreter prepare for his or her work on your behalf. The interpreter will then learn the vocabulary of the relevant products or services and will be able to provide the superior service that you deserve.