People with visual impairments often need audio description when watching TV in order to understand what is happening visually. This can be problematic in certain group settings, where it is not possible to enable audio description e.g. public viewing events. In a group setting, as of now, everybody listens to the same broadcast sound together which can sometimes make it difficult for visually impaired people to participate.
IRT has developed an application, that was successfully demonstrated at IFA and IBC 2019, to showcase the provision of audio description for TV content specifically for viewers who need it, while other viewers only hear the main sound of the television program. This idea is put into practice by supplying an additional audio stream containing only audio description that can be played over any Bluetooth enabled audio receiver. For this showcase, bone conduction headphones were used. This way, all viewers listen to the main sound on the TV together, while the visually impaired person can additionally listen to the audio description over their headphones.
The audio description is provided via internet. The viewer can select the audio stream containing only audio description by using an app on a mobile device. The “inter-device synchronization” feature of the HbbTV2 standard allows the playback of IP AV streams on a mobile device in lip-sync with the broadcast TV image. With this feature the audio description can be synchronized with the broadcast sound of the television program.
For playback of the audio description, any type of headphones can be used. However, it is important that the viewer can still hear the main sound of the TV. The advantage with bone conduction headphones is that they are placed at the temples instead of over the ears or in the auditory canal. Vibration is used to transmit sound waves to the inner ear. This means that with bone conduction headphones the TV viewer can hear surrounding sounds just as well as without headphones..
Thus, shared TV experiences for people with different needs can be enabled. The developed showcase application can already be used right now on all devices which support the HbbTV2 standard.