The acoustics of soil: an understudied topic. How can people perceive conditions? Are they natural?
Two sources state in a bucket from underground that soil matters. Soil matters for plant growth.
Nutrients and rhizomes both exist in soil(s).
Lome, mead, sand, rock… the list continues.
If soil is compressed it is more difficult for roots to puncture it (?).
If soil is too loose oxygen bubbles form in between the grains and asphyxiate the roots (?).
Thus a happy medium (sound) would travel faster through the Earth into the roots when the density is rarefied.