User-Centric Surround Sound on Headphones

All of us have two ears and together with the brain, these form a formidable aural processing system that we take for granted. In real life, these external appendages not only help in locating our position with respect to our surroundings, but also in pinpointing the sources of various sounds that surround us. For example, we instinctively move to the right to avoid a honking vehicle approaching us from behind on the left.

When enjoying the stage performance of a group of musicians playing their instruments, we can point out various instruments with reasonable accuracy, even with our eyes closed. We can do this because the sound reaching the left ear is somewhat different from that reaching the right ear and by unconsciously moving our heads ever so slightly we emphasize that difference. Our brain processes various aspects of the sounds reaching it from the left and right ears, analyzes them and forms a mental image of the position of the instrument relative to the two ears.

A similar situation is artificially created when we listen to the reproduction of stereophonically recorded sound played back through two loudspeakers placed some distance apart. Our brain is able to take in the variation in sounds and form the two dimensional aural image between the two loudspeakers. A quadraphonic or surround sound system, such as in a home theater, helps to generate a more realistic image in three dimensions.

However, when listening through headphones, the brain loses a major part of the information. Minute movements of the head produce no variation in the aural information from the two ears, as the headphone is now attached to the head and moves along with it. Therefore, surround sound through headphones does not provide the same level of satisfaction as that coming from a set of loudspeakers of a home theater – but this may be changing now.

A Neoh headphone has a 9-axis motion sensing mechanism to track the smallest micro-movement of the wearers head. The sensors comprise a magnetometer, accelerometers and gyroscopes. This is similar to the way your smartphone can sense its tilt when you play Temple Run on it.

The movement data from the headphones goes to a binaural algorithm via Bluetooth to the sound source the user is employing. This could be a game console, a smart TV, a tablet or a smartphone. The sound source processes the surround sound format making the perceived sound field remain static for the wearer.

Therefore, if the user turns his head (wearing the headphones) to the right or to the left, he or she will hear and localize the appropriate sounds respective to the original sources. The user will feel as if he or she were listening to a home theater sound system or a conventional cinema performance.

According to the company, these special headphones go far beyond stereo. The audio processing app runs with the headphones to virtualize different audio sources, thereby creating an immersive audio sphere. They claim the headphones offer a far more realistic sound experience than what users can experience with the best home theaters today.