The quality of a simultaneous interpretation depends largely on the working conditions and equipment provided to the interpreters. Poor sound insulation and visibility on the booths, defective microphones and headset systems for the delegates can all contribute to undermine the quality of the interpreting being provided and, ultimately, of the entire event.   

Good sound quality in the booths and in the conference room is an essential factor in simultaneous interpretation. Organisers need to be fully equipped with the right tools in order to meet the high standards required for successful interpretation. Poor sound quality is likely to cause unnecessary stress and fatigue. Good sound depends on many factors, including proper sound equipment that supplies the full range of sound (125-12,500 Hz); good-quality, lightweight earphones; room acoustics; loudspeakers distributed around the room and volume kept low enough.

An important design item is that "listening" and "speaking" controls not be mixed up. One way to achieve this is to confine them to distinct areas on the interpreters’ console panel. The controls most frequently used should be easily accessed – i.e. microphone on/off, tone control – should be easily accessible.

The interpreters’ console panel should be equipped with tone controls to adjust bass and treble settings according to individual preferences and different speakers' voices along with a mute button. Selectors for outgoing and incoming channels should be easy to differentiate from one another.

On the other hand, all interpreters should be equipped with individual microphones. If the microphone is attached to the control panel, it should have a long enough flexible stem so the interpreters are not forced to adopt a rigid or awkward position.

Interpreters should also be equipped with individual earphones. Earphones should be of a very high-quality, lightweight, and specially designed for interpreting purposes. They should provide audio frequencies from 125-12,500 Hz

Headsets with microphone incorporated are not recommended for permanent installation. Opinions are too divided on their use: although they can be made available to interpreters, some bluntly refuse to use them.