text: The simplest concept is the measurement made using two microphones and a fast recording device such as a digital storage scope. This method uses the following idea.
  If a sound source and two microphones are arranged in a straight line, with the sound source at one end, then the following can be measured:
  # The distance between the microphones (), called microphone basis.
  # The time of arrival between the signals (delay) reaching the different microphones ().
  Then .