Attentive focus on a particular timbre changes which auditory stream the ear follows.

Evidence

As you listen, the particles of sound (phonons) decide to be heard. Listening affects what is sounding. The relationship is symbiotic. — Pauline Oliveros, Deep Listening, 346 (#corroborates, via linked claim)

In this experiment, the rising arpeggio shown as response (A) is perceived as expected for stimulus (A) when all the note timbres are the same. However, the response changes to two separate falling arpeggii, shown as response (B), if note timbres are alternated between two timbres represented by the different notehead shapes, and “the difference in timbres is increased” as shown for stimulus (B). This is described as timbral streaming (e.g., Bregman, 1990). — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1629 (#expands, via linked claim)

Categorization

• XREF: connects to: Alternating timbres can split a single melodic line into separate perceived streams — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1629; The ear switches from place to temporal pitch coding when harmonics stop being resolved; Listening actively shapes the sound it perceives rather than merely registering it — Pauline Oliveros, Deep Listening, 346

Broader Connections

• Listening actively shapes the sound it perceives rather than merely registering it #corroborates (0.88) — Pauline Oliveros, Deep Listening, 346
• Alternating timbres can split a single melodic line into separate perceived streams #expands (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1629
• The ear switches from place to temporal pitch coding when harmonics stop being resolved #expands (0.72)