The light in the hall of the Royal Theater in The Hague slowly goes out on Wednesday evening. The room is full. Nine visitors put on black glasses. When the first actor starts speaking, subtitles appear in their glasses. They can move the text themselves so they can still see the actors clearly.
The glasses are part of an experiment by the National Theater. In collaboration with the Canadian software company XRAI, the organization developed glasses that subtitle spoken text live. The National Theater wants to make theater performances more accessible to non-Dutch speakers and the hearing impaired. In the autumn of 2025, she made the glasses available for free at various performances – a world first at the time. The National Theater is still the only one to provide glasses with live subtitles.
Regular subtitling above the stage, such as at the International Theater Amsterdam, is labor intensive, according to initiator Monique Rutten. “With these glasses, where the text is based on the voice and not on the script, it is possible to make theater with a lot of improvisation, such as cabaret, more accessible.” The actors on stage wear microphones, their voices are converted into text using language models and other artificial intelligence. The text appears in the glasses and appears to float above the stage, so that your gaze does not have to switch between far and near. The subtitles can also be translated, Rutten says to the visitors who test the glasses before the performance. “You can choose from more than two hundred languages: from Ukrainian to Icelandic.”
The nine visitors testing the glasses tonight are actively involved in the development of the technology. Some have already tested previous versions. This evening the visitors have come for the theater play Operation Hellfirethe new political thriller from director Eric de Vroedt about the International Criminal Court in The Hague. “It is a very linguistic performance, so a lot of text passes by at a high pace,” says Rutten.
For Chengfan Zhao, who came to the Netherlands from China six years ago, this is a reason to use the glasses. He hopes that the Chinese translation will help him to understand Dutch better. “Without the glasses I sometimes have to guess what they mean. Now I can just read along.”
Without the glasses I sometimes have to guess what they mean. Now I can just read along
A few seats further away sits Godert van der Feltz. He is hearing impaired and over the years has developed ways to continue going to the theater. Sometimes he requests the script in advance, sometimes he follows actors by lip reading. For him, the glasses are a hopeful solution, he says. “Without an aid I just miss too much.”
The Greek island ‘Melos’ becomes ‘Melon’
During the performance, the glasses seem to cope reasonably well with the language of the performance. The glasses I wear subtitle without any delay all kinds of different legal sentence structures, multiple abbreviations of weapons, the names of former French presidents and defense terminology. However, ‘Trump’ appears several times as ‘Customer’, the Greek island ‘Melos’ as ‘Melon’, ‘year’ as ‘hairball’ and ‘quiche’ as ‘do you choose’.
With Van der Feltz, random sentences sometimes appear in Georgian script. And the glasses cast a dark filter on the stage, says Van der Feltz. “It gives a less clear image, which you get used to during the performance,” he says. “Sometimes I took off my glasses.”
“The translation is not bad,” says Zhao, who switches back from Chinese to Dutch halfway through. “But it takes too long for the text to appear on the screen.” The text is transcribed and later converted into Chinese script by artificial intelligence. That is why the system sometimes lags a few seconds behind.
Visitors to a theater performance by the National Theater test the AI glasses, 2025.
Photo Francine van der Wansem
Development
The technology is not yet perfect, the employees of the National Theater admit. “It is especially difficult for deaf people, who are very focused on lip reading, if they see the stage less clearly,” says assistant programmer Alberto Quirico about the dark filter. That is why they are placed at the front of the room. “The system also does not recognize sounds: someone knocking, or something exploding, for example. If you cannot hear anything at all, you still miss that context.”
The National Theater is therefore working on glasses without a dark filter. And two hours before the start they performed a software update to improve the punctuation. “We conduct tests every day to improve the glasses,” says Rutten.
Van der Feltz finds the glasses valuable. “Even with these glasses I sometimes can’t follow a sentence or two. But I get so much more than if I didn’t wear the glasses. With these glasses I would go to the theater more often.”
