Welcoming Andreas Costrau: Creating Authentic German Sign Language (DGS) with Signapse

At Signapse, our mission has always been clear: to bridge the accessibility gap by bringing high-quality, photorealistic sign language to every screen. As we prepare to expand our AI-powered sign language into Germany, we know that the technology is only as good as the linguistic and cultural foundation it is built upon.

We are incredibly proud to announce our official collaboration with Andreas Costrau, who has joined us as our central language partner to help build our German Sign Language (DGS) model.

Putting Language Quality and Acceptance First

For Deaf and hard of hearing people, DGS is more than a communication aid - it is their first language and their cultural home. Currently, the vast majority of digital content goes unsigned, not out of indifference, but because qualified human interpreters are scarce and comprehensive coverage is often unfeasible.

While AI provides a scalable solution to the language accessibility gap, ensuring linguistic accuracy and community alignment is our highest priority. German Sign Language is a distinct language with its own complex grammar and cultural identity. Therefore, to build our DGS technology, we are collaborating directly with established experts from within the Deaf community to ensure the AI respects and accurately reflects the language.

This collaboration will drive the development of our upcoming DGS Digital Signers, starting with ‘Kim’ – our first DGS Digital Signer. Following Kim, our second DGS Digital Signer will be built directly from Andreas’s own appearance.

The underlying development is grounded in extensive, high-precision video recordings currently taking place at a green screen studio in Berlin. Andreas is signing glosses - the core building blocks of sign language, in front of the camera. Our Signapse technology captures his exact signs, facial expressions, and body language, transferring them photorealistically to train our models. Because our AI learns directly from native experts, the final outputs for both Digital Signers will authentically reflect the natural rhythm, depth, and cultural nuances of DGS.

Meet Andreas Costrau: Our Deaf DGS Translator

Andreas Costrau brings an unparalleled level of authority and lived experience to Signapse as a native DGS user and a third-generation member of a Deaf family. Based in Berlin, he is a state-certified DGS instructor and a highly recognised educator in his field. He is the founder and owner of Gebaerdenservice.de, a renowned sign language school offering courses, coaching, and consultancy. Furthermore, he serves as a part-time academic lecturer teaching at the Katholische Hochschule für Sozialwesen Berlin (KHSB) and works as a consultant and coach for sign language and Deaf culture within the film industry. He is also now a lecturer at the Language Centre of Humboldt University Berlin.

With recordings officially underway in Berlin, the training of our models is in full motion as we target the official market launch of our DGS solution in Q4 of 2026. This timeline allows us to meticulously refine the technology alongside our integration partner, G&L Systemhaus, who will seamlessly integrate the Digital Signers into existing streaming infrastructures via API and SDK. This ensures that institutions, broadcasters, and organisations that have previously been unable to provide sign language due to capacity constraints will complexly have an organisationally and economically viable option to make their content accessible.

As we take this massive step forward, we want to emphasise our core philosophy that this technology is explicitly designed to complement human professionals, not replace them. In sensitive or highly specific environments - such as medical, legal, or political settings - qualified human interpreters remain absolutely indispensable. Our goal is to open doors where provision was previously impossible, bridging the gap for everyday digital media, streaming, and on-demand content for the 200,000 DGS users in Germany.

‍"Working with Signapse and G&L is an important step toward establishing AI-powered sign language in Germany at a genuinely high linguistic standard. We are committed to ensuring that the Digital Signer not only signs correctly, but that the expression, rhythm, and cultural nuances of DGS are authentically represented." — Andreas Costrau

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