Mass dominates impedance at high frequencies, stiffness at low frequencies

Evidence

The impedance will depend on the frequency of this forcing. If the period (time interval between repetition of the periodic force) of the forcing is very short (high frequency), then the force is changing suddenly; not much movement of the object takes place because such a short time elapses between reversals of the force. The impedance will tend to be mass dominated. If the frequency is low and the forcing period is very long, then the force is being applied slowly; the impedance will tend to be stiffness dominated. — Eric J. Heller, Why You Hear What You Hear- An…, 87

Categorization

• DEFINE: This is the key frequency-dependence insight: impedance direction flips based on forcing rate, core to why we hear what we hear.
• corroborated: 2 independent passages support this claim — Eric J. Heller, Why You Hear What You Hear- An…, 87
• XREF: connects to: Slow forcing gives stiffness-dominated impedance; sudden forcing gives mass-dominated impedance — Eric J. Heller, Why You Hear What You Hear- An…, 86; Partition mass provides isolation at higher frequencies until coincident resonances degrade it; Impedance is minimal on resonance (+6 more)

Broader Connections

• Slow forcing gives stiffness-dominated impedance; sudden forcing gives mass-dominated impedance #corroborates (0.95) — Eric J. Heller, Why You Hear What You Hear- An…, 86
• Impedance is minimal on resonance #expands (0.85)
• Partition mass provides isolation at higher frequencies until coincident resonances degrade it #exemplifies (0.80)
• Instrument stiffness versus tension determines how widely its modes are spaced #expands (0.80)
• A medium’s intrinsic acoustic impedance equals density times sound speed #expands (0.75) — Eric J. Heller, Why You Hear What You Hear- An…, 102