Depth and spatial impression

As the Ambisonics technique only addresses the direction of the sound, not its distance, its distance- clues have to be modelled separately. The Result is a sound that may come from nearby or far away. Both, The reflected image of the sound by the environment (See Peter P. Lennox's work) aswell as an altered quality of sound itself helps to perceive a distance of a sound and a depth of field. The distance clues were also modelled in Csound and combined with the Ambisonic - technique: Relation of local/global reverb, attenuation, filtering - all according to the distance. For creating an environment, which reflects the position of the sound, spatially distributed early reflections were created. A pattern of early reflections, changing according to the position of the sound is a major clue for localisation in terms of distance. Doppler -effect is also applied according to the velocity of the sound source in relationship to the listener. All this helps to include depth of space and to emphasise the perception of motion of sounds. A great source of information and inspiration is the paper of P. Lennox presented at the ICAD which can be downloaded here.