The quote from Pierre Boulez, given as an epigraph to this article, inspired French researchers to start developing technology for spherical loudspeaker arrays in the 1990s. The hope was to retain the naturalness of sound sources. Now, a few decades later, one might be able to show that even more can be done: In electroacoustic music, using the icosahedral loudspeaker array called IKO seems to enable spatial gestures that enrich alien sounds with a tangible acoustic naturalness. After a brief discussion of directivity-based composition in computer music, the first part of the article describes the technical background of the IKO, its usage in a digital audio workstation, and psychoacoustic evidence regarding the auditory objects the IKO produces. The second part deals with acoustic equations of spherical beamforming, how the IKO's loudspeakers are controlled correspondingly, how we deal with excursion limits, and the resulting beam patterns generated by the IKO.

The transient modifier is a type of audio effect that changes the level of the transient parts in a musical signal while leaving the steady-state parts unchanged. This article presents a high-performance algorithm for transient detection and modification, one that is capable of modifying transients in polyphonic or multi-voiced signals, and capable of modifying both hard (percussive) and soft (non-percussive) transients. The detection and modification of transients are performed in the frequency-domain using a sub-band approach. Detection is based on both phase and energy information using an adaptive threshold, and modification is carried out independently at each sub-band. The performance of the proposed sub-band approach was compared with other transient-modification algorithms using subjective listening tests. We show that the sub-band approach with adaptive threshold mostly outperforms other approaches.