A small miracle happens every so often at Birmingham Hippodrome, and most people are unaware of it.

In a small booth “at the back of the circle, up in the heavens”, someone is audio-describing the stage action to visually-impaired members of the audience.

And tomorrow night’s Welsh National Opera staging of Verdi’s Otello will be the latest example of this facility, complementing the help that the Hippodrome already gives to audience members with hearing problems. Deaf patrons can enjoy “signed” performances, and “deafened” spectators (those who, having only gradually lost their hearing have never learned sign-language) can attend captioned performances, for which the Hippodrome shares equipment with Birmingham Repertory Theatre.

Liz Leck, the Hippodrome’s education and audience development manager, explains that the process begins with members of the audience who are going to listen to the audio description taking a “touch tour” of the stage.

“The audio-description is obviously somebody describing what’s actually happening on the stage, so they’ll take you through all the actions, the costumes, the set, the expressions of the people, the movements... and then they’ll stop for the dialogue. What the touch tour does, it enhances all that and is basically a tactile exploration of the set and the costumes. It gives people an idea of how far somebody has to walk across the stage, they have an idea of different set-changes – we talk them through what’s going to happen at different times – and they’ll be able to feel the set itself, things that are textured so that they can be seen from far away in the auditorium.

“A brick wall will actually feel like a brick wall, and you can feel what the floor would be like, and where the windows will be. And the costumes as well, which are a really important part of it, with all their different fabrics, and the weight of them – perhaps something which the rest of the audience wouldn’t be able to experience.

And the Hippodrome stage-crew doesn’t mind allowing the public to swarm over their domain.

“Our crew here are wonderful. They’re up for anything we do. The Hippodrome technical staff are amazing, they’ll help with anything.”

When does the describer find time within the performance to commentate on what’s going on? “Well, it’s a real art! What they have to do, they have to sit and watch it, a number of times. Our describers, Jonathan Nash and Julia Grundy, will do an awful lot of pre-preparation. But the touch tour is very important, as you can explain what happens through that. And before the performance actually begins they will have given them the whole low-down, scene by scene, painting the picture to people as to what will actually be happening onstage.

“We only began as a one-off, because a little girl asked for it.

“It was The Nutcracker, and Birmingham Royal Ballet took us backstage, because this little blind girl loved the story. She comes to a lot of our audio-described performances.”

* Details of the “touch tour” and audio-described performance of Otello are available on 0844 338 5000.