In stereophony, a distinction is made between time-of-flight stereophony and intensity stereophony. AB stereophony is a recording method that works with time-of-flight differences.
The time-of-flight method works with two microphones that are placed at a relatively small distance from each other. The stereo effect results from the time-of-flight differences between the sound signals to the two microphones and is an auditory replica of the sound events. The distance between the two microphones facing in the same direction is about 10 cm to 20 cm and can correspond to the ear distance. The directional characteristics of the microphones can be different. Depending on the selected microphone type and the associated directional characteristic, interfering room effects can be suppressed.