It's Sunday midday and you're flicking through the TV channels when you come across Fine Gael TD Gay Mitchell arguing with a member of the studio audience. At first you think its just another one of those Sunday-morning current affairs programmes.

But wait. The audience member asking the question is using sign language. Mr Mitchell, flanked by a sign-language interpreter, immediately answers the question. The TV presenter, also using sign language, invites other questions from the audience. Labour's Roisin Shortall responds to a point about the recognition of Irish Sign Language by the Government. Fianna Fail's Pat Carey talks about the importance of the new Centre for Deaf Studies in Trinity College Dublin. The PDs' Cait Keane talks about deaf school education. It all looks seamless and fluent.

The programme is called Hands On, a regular RTE series, produced by Radius Television, that has been running since 1989 and which focuses on issues relevant to deaf and hearing-impaired people. As part of the current series, there was a studio debate where, for the first time ever, members of the deaf community grilled politicians about issues relevant to deaf people, in a format similar to Questions and Answers.

It looked much like any TV studio debate featuring an audience of hearing people - except that sign language interpreter Willie White was standing beside the politicians and interpreting their answers for the deaf audience and deaf viewers at home.

Seen from the behind the scenes, however, it is clear that there were enormous technical challenges faced by the production team in making the programme - because of the obvious communication barriers between the deaf and hearing members of the production team. Meticulous pre-preparation and strong, close working relationships did the job.

One of the problems that arise in a studio production with a deaf audience and a deaf presenter is communication between the presenter and the director in the control room. A hearing presenter would normally wear an ear-piece linked to the control room to receive instructions from the director.

However, being profoundly deaf, associate producer and presenter Alvean Jones depends on sign language to communicate, so there is an interpreter on the floor who wears the "com-link" to the director and translates her commands for Alvean. Although this arrangement works reasonably well, there are some disadvantages.

"Unlike with a hearing presenter, the studio audience sees the communication between the presenter and director, which gives the perception of a hearing person controlling everything," says Bernadine Carraher, series producer and director of Hands On. "As a result, I've had to address the audience at the beginning and tell what's going on so that they'll be more used to it."

What also becomes apparent as the cameras roll is that there is a lot of stopping and starting: Alvean has to look away from the camera to receive instructions from the director via the interpreter on the floor, Bernadette Ferguson. This prevented the studio debate from progressing as smoothly and continuously as one with a hearing audience and a hearing presenter, but everyone involved was patient and considerate.

According to Jones, the nature of making TV programmes for deaf people means that there has to be a great deal of post-production work, including much editing, adding voiceovers for sign-language users, adding subtitles, and inserting footage of a sign-language interpreter in one corner of the screen where appropriate.

In addition, matching the voiceover or subtitles with the sign language on the screen can be difficult because of the major differences in grammar and structure between sign language and spoken English.

The politicians all have ear-pieces through which they receive a translation of the audience's questions from yet another interpreter, Amanda Coogan, who watches from the control room.

Once the cameras stopped rolling, everyone started to relax a little, including the politicians. However, they didn't get away so lightly. Groups of conversations quickly started to form, as several audience members took advantage of the presence of the sign-language interpreters in order to engage in an impromptu and much more dynamic debate with the politicians.