Life in the Boundary Layer

Soundfield (boundary layer vs turbulent air)

wind (turbulence) heat humidity CO₂ richness spore “kite” bursts

Mapping notes (based on the chapter)

Boundary layer depth sets how “protected” the sound is: deeper = warmer, wetter, more CO₂, slower wind.
Still air is voiced as steady vowels (FM “vocal” formants) close to the surface.
Turbulent zone is breath/noise with faster modulation and more stereo motion.
Heat trap brightens upper partials and opens a gentle high shelf.
Humidity trap increases reverb width/decay and adds a faint chorus-like detune.
CO₂ enrichment adds a low, steady drone that feeds the “photosynthesis” vowels.
Spores on setae become occasional rising streaks that jump above the boundary layer.

Controls

Boundary layer depth 0.58

Deep = sheltered forest floor; shallow = exposed rock face.

Wind (aloft) 0.44

Controls turbulence/noise above the layer.

Heat (sun trap) 0.52

Warmer boundary layer = brighter, more “alive.”

Humidity 0.62

More humidity = longer/wider reverb and slower drying.

CO₂ richness 0.55

Adds a low drone and “feeds” vowel intensity.

Spore dispersal 0.26

Higher = more frequent upward “kite” streaks.

FM voice: vowel shift 0.35

Morphs “oo → ah → ee” formant region.

Stereo motion 0.45

Boundary layer is steady; turbulence wanders.

Reverb amount 0.58

Stereo reverb (generated impulse; no files).

Master level 0.20

Start low; FM + reverb can peak.

Tip (headphones recommended)

Use headphones to hear the still boundary layer as centered vowels and the turbulent zone as wide, panned breath. Try Sunlit Rock and raise heat, then switch to Forest Log and raise humidity.