Fraunhofer Cingo®

Fraunhofer Institute for Integrated Circuits IIS


Turn mobile devices into personal surround sound theaters with Fraunhofer Cingo. Not only does Cingo enable an excellent surround sound listening experience over stereo speakers or headphones, it also provides existing stereo content with a more natural and clear sound and includes loudness optimization for listening in noisy environments. Due to this unique combination of latest developments in audio technology, Fraunhofer Cingo delivers an exceptional level of audio quality, unmatched on mobile devices.

The Nexus family of devices uses Fraunhofer Cingo for audio playback.

Working principle

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.

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.

(Please click image to enlarge.)


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.

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 distortions 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 were developed by studying and measuring the performance of a variety of different headphone models and loudspeakers on mobile devices.


Fraunhofer Cingo was developed for a more impressive surround sound listening experience on any type of mobile device. The only requirement is a set of headphones or built-in stereo front loudspeakers.


Fraunhofer Cingo is available for OEM device and service provider app integration on any platform that supports the HE-AAC multichannel audio codec. This includes Android, iOS, Windows and Mac OS X.



Fraunhofer Cingo promotional video

Fraunhofer Cingo promotional video

Nexus 7 and Chromecast Press Event - 7/24/13

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