Alan Blumlein carried out his research into binaural sound and stereophonic gramophone recording here. X reproduces 12 channels of binaural surround sound using any pair of stereo headphones. There are some complications with the playback of binaural recordings through headphones. Engineers make a technical distinction between "binaural" and "stereophonic" recording. Dynamic binaural audio was common to most headsets released that year. They then entered the main theater where they wore special headphones with binaural sound technology. Kaan is a DIY binaural microphone for sound artist. Four channel recordings, especially those containing binaural cues, create speaker-binaural surround sound. Several high-end headset manufacturers have created units specifically for the playback of binaural audio. See the article "Binaural recording for earphones". This microphone uses the user's pinna to create the binaural effect. The ZiBionic One is a binaural microphone for ASMR recording. These transmissions consisted of two-channel audio programs, binaural audio programs and a fax program. Roland Corporation also offers its CS-10EM in-ear binaural microphone set. It manipulates timing, amplitude and frequency response to produce a binaural image.