Flexibility Conceiving Relationships between Timbres Revealed by Network Analysis

Perceived relationships between timbres are critical in electroacoustic music. Most studies assume timbres have fixed inter-relationships, but we tested whether distinct tasks change these. Thirty short sounds were used, from five categories: acoustic instruments, impulse responses, convolutions of the preceding, environmental sounds and computer-manipulated instrumental sounds. In Task 1, 46 non-musicians formed a 'cohesive' sonic ordering of unlabelled icons (sounds attached). In Task 2, they categorised the icons into four boxes. In Task 3 listeners separately ordered the sounds from each of Task 2's boxes using the approach of Task 1. Tasks 1 and 2/3 revealed distinct orderings, consistent with conceptual flexibility. To analyse the orderings, we replaced conventional distance by adjacency measures, and described each system as a network (rather than spatial positions), confirming that the two task outcomes were distinct. Network analyses also showed that the two systems were mechanistically distinct and allowed us to predict temporally changing networks, modelling the observed networks as successive perceptions. Further simulated networks generated with the temporal model readily encompassed all possible pairings between the sounds and not just those we observed. The temporal network model thus confirms conceptual flexibility even in untrained listeners, clearly suitable for a composer to use.