Seventy-four recent physiological and psychological studies revolving around human perception and its bandwidth were reviewed. The brain has ever only learned about the world through our five primary senses. With them, we receive a fraction of the information actually available, while we perceive far less still. A fraction of a fraction: The perceptual bandwidth. Conscious perception is furthermore influenced by long-term experience and learning, to an extent that it might be more accurately understood and studied as primarily a reach-out phenomena. Considering hearing, time is found to be a determining factor on several planes. It is discussed how such sentient observations could be taken into account in pro audio, for instance when conducting subjective tests; and the term “slow listening” is devised.
Binaural audio is based on ear signals, that is, acoustic signals as they occur at our outer hearing apparatus such as the ear canals or the eardrums. Ear signals are sought to be captured or synthesised for reproducing them at the same location, usually by means of headphones. If the reproduction is sufficiently accurate with respect to the reference situation, the same auditory impression shall be evoked. In practice, several factors impede the realisation of this assumption, among them technical, psychoacoustic and aesthetic ones.
From a bodily perspective, ear signals represent an intermediate step in the processing chain of human hearing: they result from the outer hearing apparatus, which, by its physical properties, transforms the acoustic surrounding into a signal pair that contains spatial information to be evaluated by the brain. Capturing and reproducing ear signals therefore means to interfere with the bodily function of listening, to decouple the outer ear temporally and spatially, or to replace it, e.g., by the pinnae of a dummy head or another person. I regard this interference as a form of engineering at the human body, albeit subtle and non-invasive.
The dummy head microphone is not a pictorial representation of the human outer hearing apparatus but it is designed to take over its function: it is supposed to actually perform a partial act of hearing. In the paper, I will relate binaural audio to the human faculty of mimesis in the sense of convergence to nature by techné, leading to aesthetically effective categories such as the magic and the uncanny.
A directional sound source can produce auditory objects at distinct locations in a room by varying its directivity pattern and orientation. Recent perceptual studies could show that the direct-to-reverberant energy ratio is the most relevant cue for their distance from the listening position. The lateralization, on the other hand, is affected by the precedence effect. Thus, the azimuthal angle of auditory objects depends on signal type and time/strength of single wall reflections compared to the direct sound.
This contribution evaluates the perception of auditory objects in a virtual room regarding both distance and azimuth angle relative to the listening position. In the evaluation, listeners were asked to match the position of an omnidirectional sound source in a virtual room with the position of auditory objects created by a directional sound source in the same room. The omnidirectional source could be positioned freely on a map of the room and additional sliders for distance and azimuth angle provided simple means for fine adjustment. The evaluation examines the influence of directivity pattern and beam orientation of the directional source, as well as the signal type.
The icosahedral loudspeaker array (IKO) uses strongly focused sound beams to ”orchestrate” reflecting surfaces resulting in the perception of auditory objects at distinct locations in the room. Previous studies revealed that stationary sounds are localized more distant from the IKO in comparison to transient sounds due to the precedence effect. Nevertheless, we could show in a direct comparison using static sound beams that the application of maskers can partly suppress the precedence effect resulting in an increased distance for transient sounds. This contribution extends the study towards trajectories of moving sound beams.
Two basic staging constellations of the IKO have been shown to be feasible in artistic practice: (1) a concave setup of approx. 5 reflectors around the IKO and (2) a simpler setup without additional reflectors, typically used in smaller, rectangular rooms. A comparison of these two setups is also included in the present study of moving sound beams.