How Cingo works

On its way from the loudspeakers to our ears, sound is altered in several important ways. By the time it reaches us, it contains information about the listening environment as well as the actual musical or speech content. In addition, sound waves that arrive from different directions are shaped by our head and outer ear. Collectively, this information helps us to identify the distance and direction of a sound source.

When using headphones, this information is absent because the audio content is played back almost directly at our eardrums and therefore appears as if the sound is 'in' our head. This can lead to considerable discomfort during extended periods of listening.

But researchers have discovered that these changes in sound waves can be measured and modelled by digital filters. By applying those filters to audio signals when listening on small devices or headphones, we can achieve a spatial sound impression close to the one achieved with 'real' loudspeaker playback. This technology is called binaural audio processing and is just one feature of Fraunhofer's ground-breaking new technology, Cingo.



Fraunhofer Cingo creates an immersive surround sound experience reminiscent of the one we all know and love from the cinema.  Flexible and convenient, the technology works with a pair of regular headphones of your choice or built-in stereo speakers.


Interested in learning how Cingo works?

Virtual surround sound for headphones

With Cingo, each audio channel can be presented as a virtual sound source, e.g. as a loudspeaker in a listening room, in such a way that it is heard from a specific location and distance. The sound appears to come from 'outside of the head' and from outside the headphones. As a result, when watching movies with 5.1 content, the viewer always appears to be in the sweetspot.

Virtual surround sound for stereo loudspeakers

Dedicated speaker processing enables the virtual surround feature even when sound is played back over stereo loudspeakers, e.g. from a laptop or tablet. In these instances, the sound appears to come from outside of the device and feels bigger and more spatial, allowing for an engaging and compelling immersive experience that brings the listener completely into the audio environment.

3D immersive audio

In addition to the existing stereo or surround content, Fraunhofer Cingo supports rendering of 3D audio content with formats that add a height dimension to the sound image, such as 9.1, 11.1 or other channel confi gurations. Even more, it provides the possibility to place an arbitrary number of sound objects anywhere in a virtual space around the listener. As a result, the listener can perceive sound elements in the front, behind, from above or below and be truly immersed in a movie, game or any virtual environment with a stunning level of reality that creates an experience of “being there”.

Loudness optimization

Within a noisy environment, such as the subway or a bus, or with devices where the loudspeakers or headphones simply cannot output sufficient volume, loudness processing can be tremendously beneficial. The loudness optimization feature of Cingo delivers a natural and clear sound even in the most challenging situations while preventing unpleasant distortion or any clipping which would lead to reduced audio quality. It is particularly useful for content that is very soft or of high dynamic range.


The quality of headphones and loudspeakers can significantly limit the user’s audio experience.The equalization feature of Cingo, compensates for the lack of bass usually encountered with smartphones and tablets, and corrects any unpleasant resonance frequencies by optimizing your audio on-the-move. The innovative techniques involved were developed by studying and measuring the performance of a variety of different headphone models and loudspeakers on mobile devices.