What is virtual surround sound in Android 4.3?

July 25, 2013
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new nexus 7 stereo speakers (2)

Fraunhofer isn’t exactly a household name, but it should be, as the company is responsible for the invention of the ever-so popular MP3 format. But perhaps the company can earn some much deserved recognition with its latest venture, bringing theater quality surround sound to the palm of your hand.

The new Nexus 7 will be the first device to make use of Fraunhofer’s new technology, which will give users a cinema-esque surround sound experience through their headphones, internal stereo speakers, or with an HDMI output to their home theater surround systems. But why is this such a big deal?

You’ve probably noticed, when listening to stuff through your headphones, that although you easily have a sense of left and right panning, it’s very difficult to determine the depth of a sound. In other words, it’s sometimes hard to tell how far in front or behind you that sound originated from, which can ruin the experience when watching a high-quality movie on your tablet.

To solve this problem, Fraunhofer created Cingo, which aims to create an immersive surround sound experience that you’d be familiar with if you owned a home surround sound system. If you like to hear an example, have a listen to the video below with your headphones on.

How it works

The best way to explain the theory and implementation behind this is to imagine a scene in real life. Each source of sound, such as a passing car or your TV, travels a different distance, reflects off different surfaces, and reaches your outer ear at a different angle to every other source nearby. These minor delays, reflections, and frequency differences, created by the shape of our heads and ears, allows our brains to pick out the location of the sound, giving it “depth”.

Cingo essentially creates a “digital space” for multiple sound channels (sources), by applying various digital filters, and other algorithms, to each sound, in order to replicate the experience that our environment creates in the real world. This process is called “binaural audio processing”, which is then combined with more traditional loudness optimization and equalization techniques, such as enhanced bass for headphones, to provide a more optimal listening experience.

Bringing it to Android

From the looks of things, Cingo will be heading to Android in the new 4.3 update, coming pre-installed with the new Nexus 7, and then heading to the Nexus 10, and hopefully other Android devices, once the new update starts rolling out.

Fortunately, Cingo should work will all Android devices which use the High Efficiency AAC (HE-AAC) audio codec, as this is what allows for the management of multiple audio sources on our handheld devices.

However, surround sound will only work with source files that contain multiple audio channels. In other words, we need 5.1 surround sound movies on our devices, it just won’t work with any old video or audio file. Fortunately, Google will be offering feature films through the Google Play Movies & TV service that support HE-ACC Multichannel in the near future.

If you want to know just how awesome surround sound and binaural audio can be, I’ll just leave this video link here for your listening pleasure.

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