Mushroom: An Oracular Sound Processor

Composers of digital music today have a bewildering variety of sound-processing tools and techniques at their disposal. At their best, these tools allow composers to hone a sound to perfection. However, they can also lead us into a routine which bypasses avenues of experimentation, simply because the known tools work so well and their sonic output is so attractive. An alternative strategy is oracular sound processing. An oracular sound processor creates a derived version of its input whose characteristics could not have been fully predicted, while affording the user little or no parametric control over the process.

Investigation on localisation accuracy for first and higher order ambisonics reproduced sound sources

Ambisonics and higher order ambisonics (HOA) technologies aim at reproducing sound field either synthesised or previously recorded with dedicated microphones. Based on a spherical harmonic decomposition, the sound field is more precisely described when higher-order components are used. The presented study evaluated the perceptual and objective localisation accuracy of the sound field encoded with four microphones of order one to four and decoded over a ring of loudspeakers. A perceptual test showed an improvement of the localisation with higher order ambisonic microphones. Reproduced localisation indices were estimated for the four microphones and the respective synthetic systems of order one to four. The perceptual and objective analysis revealed the same conclusions. The localisation accuracy depends on the ambisonic order as well as the source incidence. Furthermore, impairments linked to the microphones were highlighted.