SENSITIVE HUMAN EAR

Shannon News, 9 July 1929, Page 4

SENSITIVE HUMAN EAR

SOME CURIOUS FACTS. Professor Alexander Wood, tutor of Emmanuel College and lecturer in physics, University of Cambridge, describing the ear and its functions in the course of a lecture, said: “We still hear the expressions ‘pricking up one’s ears/ although only animals can do that notv that humans have grown out of that habit of our ancestors, who did it. I know some boy-s who still boast that they can move their ears up and down, but if I were they, i. would not exhibit the fact, since it betokens too much resemblance to their hairy forefathers.” The ear was almost unbelievably sensitive and easily damaged. Speaking about pitch, he added: “By a merciful dispensation of Providence people grow less sensitive to shrill high pitch sounds as they grow older, so that by the time they- cease to enjoy such noises they r cease to hear them.

“A normal ear can hear about 300, 000 tones varying in loudness and in pitch. When a sound grows too loud it ceases to be heard, and gets into the region of feeling so that one gets a strange tickling sensation in the ear. This tickling sensation can also be felt in the tips of the fingers if held up near the sound.”'

Referring to vibrations and acoustic resonance, Professor Wood said that an army walking over a bridge might cause the bridge to collapse if the men did not break step, “because/ 7 he said, “their steady tread might just hit the natural period of the bridge. 7,1

“In the same way a singer is quite capable of breaking a glass vase by the resonance of his voice. It was inclined to disbelieve this/ 7 ho confessed, ‘ ‘ until I discovered that in one country there was a law which stated that if cocks, by their crowing, broke the neighbours 7 glass vessels the owner of the cock should be liable for the damage. 77