Resonance requires confined old amplitude returning in phase with fresh drive amplitude

Evidence

Resonance for an oscillator corresponds to alignment (in-phase condition) of force and velocity. But force causes acceleration, which increases the velocity, so resonance corresponds to constructive addition of velocity to preexisting velocity. This applies universally, to a single oscillator, a complex structure such as a string, a membrane, a plate, a solid, and even to air. — Eric J. Heller, Why You Hear What You Hear- An…, 1012 (#expands, via linked claim)

The vocal folds are a high-impedance drive; their motion is almost unmodified by any feedback from the vocal tract. This fact is perhaps the seat of the source-filter confusion: if the drive (vocal folds) do not respond to feedback from the vocal tract, how can the latter be anything but a filter? The fallacy of this statement is the essence of resonance as discussed in many places in this book: passive amplification is possible, coaxing a drive that is anyway wasting most of its power to put out more power in certain frequency ranges, without actually changing anything the drive is otherwise doing. — Eric J. Heller, Why You Hear What You Hear- An…, 1677 (#expands, via linked claim)

Categorization

• XREF: connects to: Spontaneous emission spacing reflects the frequency step producing 180 degrees of phase shift.; Confinement or wave return, not mere amplitude, is essential to resonance — Eric J. Heller, Why You Hear What You Hear- An…, 896; Resonance requires confinement of previously emitted amplitude (+3 more)

Broader Connections

• Resonance requires confinement of previously emitted amplitude #corroborates (0.95)
• Resonance is universal constructive addition of force-driven velocity #expands (0.85) — Eric J. Heller, Why You Hear What You Hear- An…, 1012
• Passive cavity resonance can amplify a drive without altering its motion #expands (0.75) — Eric J. Heller, Why You Hear What You Hear- An…, 1677