That got me thinking: what if the hum is a two-part process? First, infrasound/near-DC pressure fluctuation triggers the tensor tympani reflex. Then, in susceptible individuals, the tensor muscle twitches, spasms, or otherwise locks up.
Alternatively, it could be a resonance mode between infrasound stimuli and tension/relaxation of the tensor tympani. Eg. Pressure pulse -> TT reflex -> neural reflex drops as sound is blocked by TT -> repeat.
Total speculation, but this would explain the person-dependent experience, as well as the inefficacy of earplugs, sound dampening, etc.
Alternatively, it could be a resonance mode between infrasound stimuli and tension/relaxation of the tensor tympani. Eg. Pressure pulse -> TT reflex -> neural reflex drops as sound is blocked by TT -> repeat.
Total speculation, but this would explain the person-dependent experience, as well as the inefficacy of earplugs, sound dampening, etc.