There are several types of interpreters' booths. But whether built-in, mobile or table-top system, they all serve the same purpose: allowing interpreters to work in a quiet environment, undisturbed by outside noises that might affect their concentration. Additionally, a booth has the effect of shielding the audience from the distraction of constantly hearing the interpreters' voices, as well.
Built-in, or permanent, booths usually exist in major conference centers dedicated to the very purpose of hosting multi-language meetings. The conference venue is built with a number of small rooms attached, usually directly adjacent to the main auditorium and connected to the auditorium by large glass windows. In rare cases the interpreters' booths are located away from the conference room and are only linked to it by camera. Be it live or by means of a video screen, however, it is absolutely vital that the interpreters can see, not just hear, what is happening in the conference room and have direct eye contact with the speakers.
A built-in booth.
Mobile booths offer nearly the same degree of soundproofing as fixed booths do, but consist of lightweight wall and roof panes that can be dissembled and assembled as required. This is why this type of interpreters' booth is generally used for conferences in hotels or other venues where no permanent booths are available. Mobile booths are usually rented out by suppliers of conference technology together with the technical equipment required.
A commonly used type of mobile booth.
Table-top booths are not as soundproofed as the other two kinds of interpreters' booths. They only consist of a front and side panes placed on a table to give both the interpreters and the audience some rudimentary noise protection. Portable booths are only rarely used, however, since they are only suitable for informal occasions and do not offer the full range of features that real booths have. Therefore, table-top booths should only be used in situations where strict sound insulation is not of the essence and where the use of a walk-in booth is not possible.
A table-top booth.
When planning a multi-lingual conference, the chosen venue has to be large enough to accommodate the interpreters' booth(s). A two-person booth and the workspace required by the attending conference technician will take up some 3.5 by 2 meters (11.5 by 6.5 ft).