Simultaneous interpreting is a service essential to the smooth running of international conferences with foreign language speakers and one that allows such events to be kept within the same time frame as unilingual ones. Simultaneous interpreting requires interpreters with a high standard of physical and mental fitness, as well as appropriate technical equipment. The latter means one soundproof interpreting booth with two interpreter consoles for each language pair, and a number of headsets corresponding to the number of users of the service. Typically, two interpreters are required for each language pair to take turns every thirty minutes (or lecture by lecture as is reasonably practical).
In addition to the above, the cost of simultaneous interpreting is greatly affected by the relative rarity of source and target languages. Interpreting between the most common language pairs (such as Hungarian to English and Hungarian to German) is normally cheaper than between two non-Hungarian languages (for instance, German to English). For very special language pairs, an intermediate language (i.e. two additional interpreters) may need to be involved in the process. For example, a German to Italian interpreting assignment would probably be managed by the German message first being rendered into Hungarian and then from Hungarian to Italian. This is called relay interpreting.
Therefore, if you can choose a major world language (English, German or French) as the second language of your conference, you have already taken a step towards minimising the expected cost of interpreting services. Depending on the actual interpreting needs, the length and frequency of breaks and the availability of resources for preparation, simultaneous interpreting can sometimes be provided by a single interpreter.
It also often occurs that only two or three foreign guests need to be enabled to follow an event conducted in the local language. Such a need can be managed by whispered interpreting. Seated next to a maximum audience of three, a whispering interpreter renders what is said to the target language in a low voice and without the need for any technical equipment.