Attack and release phases lasting milliseconds largely determine a note’s timbre

Evidence

When considering the notes played on pitched musical instruments, timbre relates to those aspects of the note which can be varied without affecting the pitch, duration or loudness of the note as a whole, such as the spectral components present and the way in which their frequencies and amplitudes vary during the sound. … The onset and offset portions of a note tend to last for a short time, of the order of a few tens of milliseconds (or a few hundredths of a second). Changes that occur during the onset and offset phases, and in par­ ticular during the onset, turn out to have a very important role in defining the timbre of a note. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1454

It is then convenient to consider a note in terms of three phases: the “onset” or “attack” (the buildup from silence at the start of the note), the “steady state” (the main portion of the note) and the “offset” or “release” (the return to silence at the end of the note after the energy source is stopped). The onset and offset portions of a note tend to last for a short time, on the order of a few tens of milliseconds (or a few hundredths of a second). Changes that occur during the onset and offset phases, and in particular during the onset, turn out to have a very important role in defining the timbre of a note. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1428

Categorization

• QUESTION: Worth chasing: does slicing off the attack of a recorded note erase instrument identity? This is the mechanism behind ‘deceiving the ear’.
• SEED: Article angle: the attack phase as the perceptual fingerprint of sound — how first tens of milliseconds of any event carry most of its identity.
• DEFINE: Gives the standard three-phase model of a note — onset/attack, steady state, offset/release — the vocabulary needed to talk about timbre.
• XREF: Connects to the reader’s interest in silence: every note is bracketed by silence at both ends, and the buildup from and return to silence carries the timbral information. — connects to: An instrument’s normal attack transient is essential to its characteristic timbre; Instrument timbre determines how dissonant the same two-note interval sounds; Instrument sound envelopes are described by attack, decay, sustain, and release phases (+9 more)
• corroborated: 3 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 1454; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1428

Broader Connections

• Note onsets have staggered harmonic entry times that define each instrument’s timbre #corroborates (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1449
• Timbre depends on sound order over time, not just spectral content. #expands (0.85)
• A steady-sounding note still has amplitude envelope variation within it #expands (0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1464
• Long-term averaging obscures transient attack and release sounds #expands (0.80)