Design for all - Accessibility

In the age of the convergence of television and the Internet, it is necessary to expand barrier-free services with the help of new technical possibilities in order to provide all people with low-threshold access to media content

IRT is committed to ensuring that media access is not only possible, but also attractive for everyone, regardless of their abilities, through all distribution channels. It develops concepts for uniform access to barrier-free services and shows how additional services can be produced and distributed more efficiently. In the cross-cutting topic of "accessibility", own solutions for subtitles for the deaf and hard of hearing and speech intelligibility will be developed, but also the know-how from other subject areas such as artificial intelligence and portals will be used.


Subtitling is an essential service for barrier-free access to today's media content. Subtitles are used by deaf or hard of hearing viewers to follow dialogue on television or streaming services. It also enables interested viewers to read the translation of a foreign-language dialogue in text form.

IRT supports broadcasters in disseminating their subtitle offerings in the media libraries. Among other things, the focus is on the implementation of the uniform subtitle format IMSC, which is intended to ensure the smooth delivery of subtitles via the Internet. IRT develops open source software for the conversion of existing subtitle formats. In addition, IRT deals with the distribution of (live) subtitles for Internet streams on desktop and mobile devices to ensure that European and international standards are taken into account.

With the subtitle conversion framework SCF and the subtitle validation engine Subcheck, IRT is working on two open source tools for subtitle conversion and validation. Therefore a continuous workflow is determined and described, furthermore ways to the realization are pointed out. The aim is to produce the subtitle only once, for all end user devices and distribution channels. An automated generation of subtitles with the help of AI is also considered. More about this


Speech intelligibillity

Speech intelligibility is not only an issue for people with normal hearing, but also for the hearing impaired. This applies to both hearing aid users with moderate to severe hearing loss as well as slightly hearing impaired people who are not yet necessarily dependent on a hearing aid - for example in the case of age-related hearing loss.

For example, when recording, so many background noises are often recorded with the speech track that it becomes almost impossible for people with audio impairments to understand the speaker. Simply making the voice track controllable does not help here, since amplifying the voice track would also amplify the ambient noise it contains. In order to counteract this problem, IRT is developing an algorithm that is intended to separate the pure speech signal from a complex audio signal.

In order to generally improve the possibilities for the distribution of a more speech intelligible audio signal, IRT works together with broadcasting and industry on the evaluation and further development of existing technical solutions, as well as on the international harmonization of subtitle technologies.

Accessibility in immersive environments

In the case of immersive media offerings, there is still a lack of experience how content for hearing and visually impaired users can be communicated barrier-free. The EU project Immersive Accessibility (ImAc) is investigating how the corresponding additional services (subtitling, audio description, audio subtitling, sign language) can be optimally integrated into the new immersive media. The most important measures within the framework of ImAc are to make immersive experiences inclusive, taking into account different languages and responding to the needs of people with hearing and visual difficulties, learning difficulties and different ages.

Already in the EU project 2-Immerse, Augmented Reality (AR) was used to demonstrate how virtual objects can be projected into the real environment. In cooperation with ARD-aktuell and Phoenix, a prototype application was presented at trade fairs which shows how TV programmes can be projected around a sign language speaker who is projected into the viewer's field of vision via AR glasses.

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„One-Button“ principle

In addition to the need-based design of the services themselves, simple and uniform access to all barrier-free (additional) services is necessary. For this purpose, IRT is developing a "one-button" concept, whereby users are offered the option of opening a menu at the touch of a button in which the various access services for audiovisual content can be activated.