Effective flow resistivity is the dominant ground absorption parameter.
Evidence
These examples show that hard boundaries, i.e., those with a high effective flow resistivity, act as good reflectors and have little effect on pulse waveforms, while soft, absorbent boundaries with low effective flow resistivities can produce radically different waveforms by absorbing the higher frequencies. Additional calculations (omitted here) revealed that the three other parameters involved in Attenborough’s model have an influence on the waveforms smaller than that of the effective flow resistivity. — Donald G. Albert and John A. Orcutt, Acoustic Pulse Propagation Above…, 73
Categorization
- XREF: Directly satisfies the polyad need: explains the physical mechanism of why snow (low resistivity surface) absorbs high frequencies and elongates late-season recordings — directly relevant to Soundscape Ethnography ground-impedance confounds. — connects to: Snow exceeds other natural surfaces in sound absorption by a large margin. — Donald G. Albert and John A. Orcutt, Acoustic Pulse Propagation Above…, 6; Snow grounds require a layered porous-medium impedance model. — Donald G. Albert and John A. Orcutt, Acoustic Pulse Propagation Above…, 26; Ground impedance, not foliage, governs low-band attenuation by vegetation. — Donald Aylor, Noise Reduction by Vegetation and Ground, 2
Related
- Snow exceeds other natural surfaces in sound absorption by a large margin. (similarity 0.90)
- Snow is the most sound-absorbent natural ground cover (similarity 0.88)
- Snow grounds require a layered porous-medium impedance model. (similarity 0.87)
- Donald G. Albert and John A. Orcutt — Acoustic Pulse Propagation Above Grassland and Snow Comparison of Theoretical and Experimental Waveforms (similarity 0.83)
- Ground impedance, not foliage, governs low-band attenuation by vegetation. (similarity 0.82)
- Acoustic sensing can measure snow permeability at spatially averaged, selectable scales (similarity 0.82)
- Prior noise studies conflicted after omitting ground attenuation as a variable. (similarity 0.79)
- Ground and vegetation attenuate noise in complementary frequency ranges. (similarity 0.79)
- Ground-effect interference fades at higher frequencies and longer ranges (similarity 0.79)
Broader Connections
- Ground impedance, not foliage, governs low-band attenuation by vegetation.
#expands(0.72) — Donald Aylor, Noise Reduction by Vegetation and Ground, 2