Denser materials slow sound while stiffer bonds speed it up

Evidence

For longitudinal waves in solids, the speed of propagation is only affected by the density and Young’s modulus of the material … However, although the density of a solid is independent of the direction of propagation in a solid, the Young’s modulus may not be. For example, brass will have a Young’s modulus that is independent of direction because it is homogeneous, whereas wood will have a different Young’s modulus depending on whether it is measured across the grain or with the grain. Thus brass will propagate a disturbance with a velocity that is independent of direction, but in wood the velocity will depend on whether the disturbance is traveling with the grain or across it. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 64 (#expands, via linked claim)

Categorization

• XREF: connects to: Thick shrubs barely block noise because they act as a slower continuum; Real string stiffness slightly raises wave velocity with frequency, affecting timbre.; Higher material density slows sound propagation speed (+4 more)

Related

• Sound speed in solids depends only on density and elastic modulus (similarity 0.90)
• Shape-dependent spring constants make vibration speeds complex in solid objects (similarity 0.86)
• Medium density and elasticity shape the pressure-velocity amplitude relation (similarity 0.85)
• Higher material density slows sound propagation speed (similarity 0.84)
• Real string stiffness slightly raises wave velocity with frequency, affecting timbre. (similarity 0.83)
• Acoustic refraction parallels optical refraction via material-dependent wave speed (similarity 0.83)
• Wood’s anisotropy makes sound radiation direction- and frequency-dependent (similarity 0.83)
• Wood grain direction drastically changes the speed of sound through the material (similarity 0.82)
• Thick shrubs barely block noise because they act as a slower continuum (similarity 0.82)
• Instrument stiffness versus tension determines how widely its modes are spaced (similarity 0.80)
• Wave propagation speeds depend on shape beyond simple strings (similarity 0.79)
• All acoustic impedances are ratios of force to velocity (similarity 0.79)
• Shear waves resist deformation via stiffness rather than tension (similarity 0.78)
• A medium’s density and elasticity relate sound pressure to particle velocity. (similarity 0.78)

Broader Connections

• Higher material density slows sound propagation speed #corroborates (0.98)
• Sound speed in solids depends only on density and elastic modulus #expands (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 64
• Shear waves resist deformation via stiffness rather than tension #expands (0.75)
• A string’s stiffness raises its higher-frequency modes above the ideal values #expands (0.75) — Eric J. Heller, Why You Hear What You Hear- An…, 860
• Medium inertia produces a time lag in disturbance propagation through a material #corroborates (0.72)