If no common language can be found for a meeting then you may need to use interpreting. There are a number of different ways to provide interpreting for a meeting. Simultaneous interpreting is the kind of interpreting used at the UN or the EU Parliament. Interpreters sit in booths with headsets and microphones and interpret only a few seconds behind the orator. Participants listen to their chosen language through headsets.
This is ideal for equal participation. If the interpreter is good, all participants hear what is said at more or less the same time, in the language of their choice.
The main problem is that it requires a technological infrastructure: booths and complex sound technology for interpreters to listen to the meeting in one language and transmit to listeners in another language.
Interpreting systems can be professionally hired but they are very expensive.
This is why we believe that self-made conference interpreting systems are politically important. Reducing the cost of interpreting equipment can make our political processes more accessible and more participatory, for example providing for more minority languges, or providing interpreting for smaller working group meetings and not only the big. plenary events.