Humans have good sensors. (Of course, some creatures have far more amazing versions of the sensors, such as the eagle’s eye, or the elephant’s ear.)

We can see when there is only an average of one photon per second reaching our eye (near yellow-green wavelengths). How many orders of magnitude higher can we tolerate?

We can hear on a logarithmic scale from zero to 120, but that doesn’t even begin to describe how good and broadly-encompassing our auditory sensors are. (And we can hear sounds as loud as they go, but as sound energy and intensity increases it will eventually wipe out our ears, or even kill us.)

Pressure? We can feel the slightest breeze, usually notice a mosquito land, but can handle impacts exceeding 25 mph, or the pressures of our opponents blows in the boxing ring. It is really remarkable when you think of it.

Our temperature sensing is not so impressive, but still good. We cannot tolerate 200 K. It is too cold. We are freezing even at 270 K. We say it is warm by 300 K, and we are claiming it is hotter than Hades by the time it is 312 K. On average, people cannot tell the difference with a one degree Kelvin change, two degrees for many people, yet some careful record keeping with a good thermometer and hygrometer should quickly convince you that temperature perception is probably the most subjective of our senses. In an environmentally controlled laboratory, where the temperature and humidity are controlled to about ±1°F, and humidity is controlled constant within ±5%, one can feel hot one day, cold the next, and everything in between, and that is with consistent desk work. Add in variations in activity and exertion, and the subjectivity and discomfort can increase further!

Back to the absolutes. We cannot live at 200 K. It is just not possible; it is much too cold. However, only 33% higher, and we think it too warm. Then again, given the subjectiveness of it, many people prefer 300 K. A few prefer even warmer, perhaps as high as 310 K.

Most of us like our temperature real close to 296 K. (23°C for most of the world, 73°F for those in the USA.) Note that most of us consider a simple 1% increase to be too warm for comfort.

Now, if someone who preferred temperature at 310 K asked for a meeting room to be set to that temperature, those in charge would refuse. That is unsafe. We would likely have people faint from the heat. (We managed before air conditioning, but let’s leave that out for now.)

Why do we consider sound levels differently?

Rarely does sound we are listening too need to exceed 70 dBA. 76 dBA is twice as loud as loudness is measured on this scale, most people will subjectively judge 80 dBA to be twice as loud sounding. We recognize that just a couple of percent change in temperature can be not only uncomfortable, but unsafe. Why do we not recognize that doubling the sound pressure level (100% increase) can be even more uncomfortable? Further, why do we not recognize that increasing the levels to where we can subjectively tell they are doubled damages our hearing, at least for some of us? Are those who are hypersensitive to sound worth less; can we ignore them? Continuing on in this vein, 85 dBA is generally recognized as a level causing injury to the ears and hearing mechanisms of most people, injury that becomes permanent with increases in exposure time. Why would those in charge of a meeting be more concerned about a temporary effect on someone due to overheating, than to a permanent effect reducing someone’s hearing ability?

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