This interpreting technique is used in meetings where 2 or 3 people do not understand the main language. As in simultaneous interpreting, in chuchotage (also called whispered interpreting) the interpreter translates while the speaker delivers his/her speech.
The difference between the two techniques is that in chuchotage the interpreter does nor translate sitting in a booth and his/her rendition is not transmitted through microphones and headsets. In chuchotage, the interpreter sits behind the delegate who needs the translation, which the interpreters whispers into his/her ear. With this technique, an interpreter can interpret for maximum 3 delegates.
As no booth, microphone and headset is required, chuchotage is much cheaper than simultaneous interpreting in terms of equipment.