The size and conditions of translator cabins are regulated by the standard ISO 2603/06.75, the newer DIN 56924 (fix cabins: DIN 56924-1, mobile cabins: DIN 56924-2), IEC 914 & 764, ISO 4043.

The interpreter cabin for two persons must be at least 1.60 meters wide and deep inside and must have an inside height of 2.00 meters. A cabin for three persons must be 2.40 meters wide inside.
Sufficient ventilation and good illumination is necessary.
A very important point is also to provide eye-contact with the person to translate and screen presentations etc.

The interpreters must have a direct audio feed from the occation to the interpreters' headphones. The booth is equipped with a translator microphone station. The translators audio feed is then normally connected to the wireless transmission.
Sound-proofing is also very important. Persons who are seated close to the interpreter booths do not want to hear two languages at once.