Apple Patent Shows a “Binaural Audio” System for the AirPods Pro

• Apple has been working on a binaural audio system since 2017, and we may see it in the AirPods and HMDs in the future.
• The system calculates the listener’s head position and attenuates the sound waves accordingly.
• Binaural audio would take the AirPods wearer’s immersion to the sky if combined with spatial audio.

The spatial audio may not be the only thing that Apple is looking into in order to increase the AirPod user’s acoustic immersion. According to a newly published patent that has been picked up by “Patently Apple,” we could soon get a binaural audio system in head-mounted displays (HMD) and the AirPods Pro. That would take immersion at a whole new level, especially when gaming in VR or when watching a horror or action movie.

But what is binaural audio anyway? Put your headphones on (doesn’t work with speakers) and play the following video.

If you just jumped to answer the door, that’s immersion happening right there. You see, the binaural sound is a special sub-type of stereo 3D sound that takes into account the location of the human ears and the distance between them.

Subtle delays and small waveform frequency changes between the sound waves that reach your left and right ears are the result of human physiology. The human brain is capable of perceiving these slight differences in the two waves, and by comparing them, it’s able to tell where the source is, and this is also what’s making binaural audio sound so realistic.

Related: AirPods Update Introduces “Automagic” Audio Switching and Spatial Audi

As not everything has been recorded by binaural microphones, Apple obviously needs to perform a trick here. As the patent describes, a head-tracking system will be placed against virtual audio sources, so the listener’s position and ears orientation will be constantly tracked and re-calculated.

Based on this, the left and right channels’ sound will be modified as required, creating a realistic binaural audio effect. The patent uses an iPhone as the anchor for calculation and reception of head tracking data. In the case of the HMD, the base station of the glasses is used for this purpose.

Apple even mentions the capability to simulate sounds that come from sources at azimuth and elevation angles, so we’re not talking about one direction here, but a fully-fledged 3D system.

If spatial and binaural audio were to be combined in the AirPods Pro, watching a movie with them on will be a totally addicting experience for sure. Hopefully, this patent won’t stay on paper for long, although it looks like Apple’s engineers have been working on this since 2017.

Considering what other tech giants have been able to materialize recently, this patent may have more chances to come into fruition than usual.