Instrument timbre develops over time as higher harmonics fade in after the fundamental.

Evidence

The higher harmonics enter one by one approximately 80 ms after the fundamental starts. The rather long note onset phase is characteristic of a flute note played with some deliberation. The periodicity in the waveforms develops gradually, and in all cases there is an appreciable time over which the amplitude of the waveform reaches its steady state. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1452

Categorization

• XREF: Connects to attack transients and ADSR envelopes in synthesis, and to why synth patches layer detuned oscillators with slow filter envelopes. — connects to: Timbre depends on sound order over time, not just spectral content.; Note onsets have staggered harmonic entry times that define each instrument’s timbre — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1449; Violin timbre changes with direction as high frequencies become increasingly directional — Eric J. Heller, Why You Hear What You Hear- An…, 1785 (+15 more)
• SEED: Angle: ‘the first 80 milliseconds’ — how attack transients, not steady-state spectra, let listeners identify instruments.

Broader Connections

• Note onsets have staggered harmonic entry times that define each instrument’s timbre #corroborates (1.00) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1449
• Musical instrument notes have a gradual onset before steady state #corroborates (1.00) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1478
• Timbre depends on sound order over time, not just spectral content. #corroborates (0.95)
• Note-onset timbre differs measurably across instruments and lasts tens to 160 milliseconds. #corroborates (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1489
• Violin timbre changes with direction as high frequencies become increasingly directional #complicates (0.85) — Eric J. Heller, Why You Hear What You Hear- An…, 1785
• Instrument tuning relies on high harmonics because pitch changes there are easier to hear #complicates (0.85) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1056
• Bright timbres stem from strong energy in harmonics above the seventh #qualifies (0.80)
• Timbre can be graphed as relative energy across fundamental, resolved, and unresolved harmonics. #qualifies (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1488
• Timbre is conditioned entirely by the strength and presence of overtones #complicates (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1426
• Instrument timbre differences stem from harmonic spectra that shape masking breadth #qualifies (0.75) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 449
• Timbre reduces to a weighted ratio of fundamental and resolved versus unresolved harmonics #qualifies (0.75)
• Nonlinear distortion generates new frequencies that change timbre with volume #complicates (0.75)
• Even steady-state musical notes vary in amplitude envelope over time. #qualifies (0.75)
• Having all harmonics up to the fifth or seventh also shapes timbre #qualifies (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1477
• String stiffness makes higher frequencies travel faster, changing timbre #complicates (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 103