Whereas earlier eras of audio were about filling up big spaces with sound, headphone-delivered audio (including in VR) can benefit from the sense of 3D immersion that binaural audio provides. (Our outer ears, or pinnae, dramatically alter incoming sound waves our brains understand these alterations as directional cues.)īinaural audio has been around for centuries, but the rise of headphones and handheld audio devices has brought it back to the fore. One of the most effective approaches, which has made its way into VR, is “binaural” or 3D audio.īinaural literally means “two ears,” but binaural audio is a far cry from traditional audio.īinaural recording systems attempt to recreate the way the human head captures sound: Audio is recorded through microphones placed on both sides of a stand or dummy head (on the spots where our ears are) – enabling the microphones to capture level and time differences (aka ITD and ILD) just like our actual ears would.īinaural microphones are typically housed in cavities that look just like the outer ear, which further improves their ability to capture audio in a way that sounds natural upon playback. Capturing audio in three dimensionsĪudio companies have long tried to recreate location cues to better emulate real-world audio. Distance localization is another concern, which we compute using cues around loudness, reverberations, and the time delay between an event taking place and the sound reaching our ears.Īll of these considerations (among others) play into the development of VR audio technologies, which use specialized recording systems and algorithms to mimic natural audio. These localization cues are just a few of the factors our brains consider when determining sound position. To do that “localization,” we clue into the ways that sounds originating from different directions interact with the geometry of our bodies differently: The unique shapes and sizes of our heads, necks, torsos, and outer ears cause changes in sound filters and reflections – known as spectral modifications – that our brains use to infer direction and elevation. Our brains also need to recognize the location of sounds in front or back of us, or above or below us. Interaural level difference (ILD), the difference in sound pressure level reaching the two earsĪnd that’s just right to left.Interaural time difference (ITD), the difference between the times sounds reach the two ears.We recognize lateral direction – aka a sound’s position to our right or left – using factors such as: Sound location, in particular, is computed by the brain based on cues for things like direction and distance. So when it comes to visuals, we still “see” VR media through the same process we use to see anything else. That information is then communicated to the brain, which uses it to recognize the locations of visuals in the path of sight. When we use our eyes to see, the receptor cells of our retinas recognize the way light illuminates virtual or physical objects. Our brains process sound and visual inputs in very different ways, posing challenges for simulating alternate reality in VR. How the brain ‘localizes’ sound positionĬREDIT: Ossic How the brain ‘localizes’ sound position.

The latest advances in VR audio technology – including sophisticated “spatial audio” solutions – are making improved sound “localization” possible in virtual environments. That’s why audio has become an important area where VR leaders are focused on innovation.

Barbershop binaural sound