Just a note - typically, at least in the past, hydroelectric generators are designed to run at a much lower RPM than what you find with typical gas and steam turbines. Typically, a steam turbine generator is designed to run at either 3600 RPM (2-pole) or 1800 RPM (4-pole), but the hydro-electric generators I've seen have a much greater number of poles, and thus operate at considerably lower RPM.
I read that Hyatt generators run at 200 RPM, but that is unconfirmed. TVA's Raccoon Mountain Pumped Storage units operate at 300 RPM. A chart in the link below shows some typical hydro plant design RPM...
Bringing up the turbine was that it is one of the "new" variables to Hyatt (and possibly to a new variable the locals have not had before). The key to this new turbine - if for example it may be linked to "hum" - is the hydrostatics of the turbine blades (if the blades are of a slightly more efficient curvature & geometry to the other older turbines). Thus any slight difference in the system may create a differential pulsation in the water with respect to the other turbines. When you are dealing with megawatts of power, these tiny differences can have very interesting effects - if it hits a resonance (cavity resonance, etc).
(note: there are other complex harmonic effect factors such as inductive-capacative phase shift balance of source to transmission line load).
The human body has UELF resonances that make people physically ill. Almost a century ago, engineers at large industrial factories in France discovered the source to be infrasound pulsations developing in large cavity & pipe structures within the factory. The workers complained of feeling sick yet no-one was able to detect any particular sound (below human ear freq range). Engineer isolated the frequency to the torso frequency of the human body near 7.5 to 7.8h (note: 7.5hz is a perfect 8x subharmonic of 60hz). The military heard about this and then classified it to develop UELF infrasound weapons to incapacitate people. Since then, other infrasonic frequencies have been discovered for the head (cranial cavity & brain) and extremities. The most modern advanced (non public) tech is seizure inducing & near instantaneous incapacitating is classified but it is real - (photonic based) (no limit to weapon research).
So there is much that can affect people in symptoms from resonances. If the reports are accurate on something affecting the locals on Kelly ridge, it may be from a "new" variable - such as from what is operating below in the megawatt power levels. Just to make a point in answering a person's question in a post - I would eliminate this first of a potential "source" in contrast to the prior question on a person's youtube's conclusion it is from a phased array transmitter system.