Mics that record in 3D ambisonics are the next big thing
Ambisonics is a fascinating technology. It's basically the same concept as differential stereo encoding (where you record an R+L and R-L channel and use them to derive R and L, or just play the R+L channel for mono) extended to all three axis to create surround sound (so you have a sum channel, a horizontal difference channel, a vertical difference channel, and a depth difference channel). This was all developed in the 70s (and thus out of patent today) but abandoned for more direct means of encoding surround since it was more complex to process the signals for not much gain.  Of course now with DSPs the signal processing is much easier and with VR there's suddenly a niche for it to fill since it fully preserves the 3D soundscape (unlike e.g. 7.1 surround which only records 7 point sources at fixed positions).<p>On a side note, the upcoming 1.3 release of the Opus codec is adding support for Ambisonics-encoded surround sound.