Speaker
Description
When we listen to music, our auditory system performs a complex task known as auditory scene analysis. This process involves organising overlapping acoustic signals into distinct streams or sources, such as an instrument or a singing voice, and perceiving individual sound events, such as the notes played. The current project focused on investigating selective attention in multi-instrument music scenes – in other words, the ability to attend a target instrument while ignoring other simultaneous sources. A selection of scene features was systematically varied to study the effect of (1) scene size (1,2 or 4 playing instruments), (2) scene density (by changing the distance in frequency between target and distractor instruments) and (3) scene timbre (homogeneous vs heterogeneous set of instruments) on performance. The music pieces were taken from chorales of JS Bach and were chosen for their relative homogeneity in terms of rhythm, harmony and individual melodies. The task was to track a target melody - the “soprano” part (highest-pitched melody) or the “bass” part (lowest-pitched melody) - and indicate each time two consecutive notes were the same. Listeners tended to be better at following the soprano compared to the bass. Performance decreased with increasing scene size, and an interaction demonstrated that this effect was stronger when listeners focused on the bass than on the soprano, which may be due to a “high-voice superiority” effect. Performance also decreased with increasing scene density for both soprano and bass, demonstrating an effect of informational masking related to the distance to the target melody. Preliminary data suggest that timbral heterogeneity helps towards source segregation.