What you may not know
In the most popular form of simultaneous interpreting the interpreter sits in a booth wearing a pair of headphones and speaking into a microphone. Strictly speaking, "simultaneous" is a misnomer: the interpreter can't start interpreting until s/he understands the general meaning of the sentence. Depending on how far in the sentence the subject and the verb are located, the interpreter into English may not be able to utter a single word until s/he heard the very end of the sentence in the source language! This should make it evident how hard the task of the interpreter really is: s/he needs to be translating the sentence into the target language while simultaneously listening to and comprehending the next sentence. You can experience the difficulty of the task even if you are monolingual: just try paraphrasing someone's speech with a half-sentence delay, making sure you understand the next sentence while paraphrasing the previous one.
One of the key skills of the simultaneous interpreter is decisiveness: there is simply no time to weigh the merits of variant translations or to recall just the right idiom in the target language. Any delay and you may loose a few words (and possibly a thought) that the speaker uttered. And since the speaker may be far away, or even in a different room than the interpreter, the loss may be permanent.
Qualifications of a good interpreter
Interpreters find it difficult to make a living from the art if they don't possess, at a minimum, the following skills:
- Knowledge of the general subject of the speeches that are to be interpreted.
- General erudition and intimate familiarity with both cultures.
- Extensive vocabulary in both languages.