Human factors (John Vince book)

(a) Human ears as accelerometers are sensitive to acceleration of 1 degree per sec. per sec.

(b)Young person’s hearing frequency is from 20 Hz to 20000 Hz, but a middle aged man in high frequency can be reduced to 14000 Hz. Most bats can gear up to 100000 Hz, while dogs can hear from 40Hz to 60000 Hz.

(c) Human visual acuity can see two bright points of light separated 1.5-2.0 mm at a distance of 10 meters (40 seconds of arc, 2 microns on the retina). This is equivalent to seeing a new 60 inch LCD display of 2000 by 2000 resolution placed 4.4 meters away. (16:9 TV, 52 inch in length, 1.32m)

(d) The receptors (Pacinian corpuscles(Pacinian微粒子)) beneath the surface of the skin will respond to frequencies from 30 to 700 Hz.