SENSITIVE HUMAN EAR

Evening Post, Volume CVII, Issue 96, 27 April 1929, Page 20

SENSITIVE HUMAN EAR

SOME CURIOUS FACTS

Professor Alexander Wood, tutor of Emmanuel College and lecturer in physics, .University- of Cambridge, clo'i scribing the., car and. its functions in .the.course of a lecture, said: "Wo'still •h'ear'tho;exprcssions ''pricking up pile's oars,' although only, animals can do that now that humans have grown out of that habit of our ancestors, who did it. I know some boys who still boast that they can move .theiv ears up and down, but if I wore they I would not ,'oxhibit. the. fact, since it betokens too much resemblance to their, hairy, forefathers." •" ' . ' . ' ' 'The ear was almost..unbelievably sen-. sitiveand 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 cease to hoar them. "A normal*ear can hear about 300,----000 tones varying in loiidness and in pitch. When a sound grows too loud it ceases to be heard, anjd 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'. tip near the.sound."' . Referring to vibrations. and acoustic resonance, 1 Professor Wood said that an army walking over a bridge might cause the bridge to collapse if the men did not break step, ".because," he | said, "their, steady tread might just Jiit'the natural period of the bridge." "In the same way a singer is quite capable of breaking a glass vase by the resonance of his voice. I was [ inclined to .disbelieve this," he confessed, "until I discovered. 1 that in one country there was a law which stated that if. cocks, by their crowing, broke the ■ neighbours' giass- vessels tho ownI er'of-the cock should beiliable for the damage." • • i '