Whether a sound parses into separate notes is decided by perception, not physics

Evidence

Pitch perception is very subtle; we devote a great deal of space to it in chapter 23. A sound may parse (in human perception—there is no absolute physically correct answer) into two or more “notes,” each carrying a perceived pitch, which may or may not be related by a common musical interval. — Eric J. Heller, Why You Hear What You Hear- An…, 1701

Categorization

• XREF: Foreshadows chapter 23’s pitch perception discussion; ties to auditory scene analysis and the subjectivity of hearing. — connects to: Sonic processes are subjective and require a focal species to be identified. — Almo Farina, Soundscape Ecology: Principles,…, 210; Whether a sound counts as noise depends on subjective interpretation, not acoustics — Almo Farina, Soundscape Ecology: Principles,…, 1025