3D audio (three-dimensional audio)

3D audio is the use of binaural sound systems to capture, process and play back audio waves. The goal of 3D audio is to provide the listener with an audio experience that mimics real life.

3D audio recordings are made with two microphones mounted inside a human-like head and place where the human's ears would be. The microphones capture sound simultaneously through two channels and software adjusts the recording to mimic the slight variations in signals that occur when each ear sends signals to the brain, a concept known as biomimicry. Unlike surround-sound, which requires the use of multiple external speakers to provide directional audio sources, 3D audio can only be experienced through headphones.

Audio holograms that can replicate a 360-degree field audio experience and adjust for the disparate arrival time and amplitude of signals caused ear placement, have practical applications for training simulations and educational applications. 3D audio technology is expected to play an important part in both virtual reality (VR) and augmented reality (AR). Binaural 3D audio is particularly well suited to these emerging technologies because recordings are somewhat easy to produce and unlike specialized VR headsets, which can be quite heavy, 3D audio can be consumed through ordinary stereo headsets.

As is often the case with emerging technologies, there is an abundance of proprietary technologies and a lack of standardization with regards to audio holography. Licensing for 3D audio recording and processing technoloies can be quite expensive.Vendors associated with 3D audio include Dolby, 3Dio, Auro, Dysonics, Ossic, RealSpace, Sennheiser and VisiSonics.