Conference interpreting is often the most visible form of interpreting. It is often connected with the activities of large international organisations, such as the EU or the UN. Erja Tenhonen-Lightfoot says one of the most important skills of a conference interpreter is being able to anticipate what subjects will be touched upon in a session.

“In conference interpreting, there's always a script of sorts. A major part of the training of a conference interpreter involves familiarising yourself with the structures of society and the organisations and goals of international institutions. For example, speeches at the United Nations often involve peace, equality and human rights, and the openness of society.”

A particular challenge in the job of a conference interpreter consists of the names, numbers, and abbreviations that crop up. For this reason each interpreter booth has at least two interpreters at a time working together.

“When numbers, names, and abbreviations come up, the one who isn't interpreting writes them down on a piece of paper. The active interpreter can then look them up there. Numbers are stored in the brain somewhere in a different place from language. And proper names are difficult because they have no direct denotation to the person.”

In 2002 Ms Tenhonen-Lightfoot founded Sanas, a company that offers conference interpreting services.

“A major part of our work consists of educating our customers and assembling teams of interpreters. When you're putting together an interpreter team for a customer, you must remember to explain that there are two kinds of simultaneous interpreting: the one-way interpreting used by international organisations and the two-way interpreting often used on the open market.”

Organisations such as the EU and the UN use the “matrix” scheme, where each booth outputs only one language, i.e. each interpreter basically interprets into their native language. But in the “cartwheel” scheme frequently used on the open market, each booth works in both directions.

“The advantages of the model used by international organisations are the minimisation of intermediary languages and also the fact that the absence due to illness of a single interpreter does not affect the rest of the interpreting system. However, the “cartwheel” scheme needs fewer interpreters and thus is cheaper, but it is significantly more fragile because all the booths affect one another. Moreover, it maximises relay interpreting over another language. Whenever I'm putting together an interpreting team like this, I have to draw a diagram for myself. This is what is known as the higher mathematics of interpreting.”

The need to staff each interpreting booth with more than one interpreter comes from the professional ethics of interpreting, according to which you may not interpret between two foreign languages, or over two relay languages.

“Almost no one can interpret between two foreign languages, and each relay language compounds the risk of misinterpreting. Of course, if it's an emergency and you can save somebody's life by interpreting between two foreign languages, that's different. But the basic rule is that one of the languages must always be the interpreter's native language.”