Litchfield enquirer., 1880-02-19

MOVING THE EARs.-The power of moving the ears is usually absent in man, and it has been supposed that as man advanced in civili- zation, the power of moving the ears volun- tarily gradually became less and less until it was lost. Sometimes, however, persons are met with who can still voluntarily move their ears. It is narrated of Albinus, who was Professor of Medicine in the University of Leyden about the middle of last century, that he was in the habit of removing his wig in order to demonstrate to his class the power he possessed of moving his auricles at will. The power which many animals have of directing their cars toward the supposed source of sound, or of erecting them in an act of atten- tion, is familiar to every one. To many animals the external ear no doubt acts as a kind of artificial hearing trumpet, so that or dinary sounds may be augmented and faint sounds rendered audible. The auricle is small in mOles, seals, and walruses but it is largely developed in some bats and in the African elephant. The ears of the mouse and of the hedgehog are delicate organs of touch. In birds, the aurice is wanting. It is remark able. however, that in nocturnal birds, such as many owls, the feathers can be elevated round the ear-opening so as to form a kind of exter- nal ear. In some aquatic mammals, such as in certain seals, the sea otter, etc., the opening
 
 speaking generally, that 8 fully formed auri- cle is found only in mammals whose habits are terrestrial, and that it IS reduced in size, or, it may be, is absent, in mammals living un- der ground or in water. It was once suppos- ed that It had no function in man, and it was stated that those who had lost the external ears from accident or injury did not appear to suffer any diminutiOn in the power of hearing. Recently, however, it has been shown, more especially by Dr. Burnett, of Philadelphia, that the external ear, instead of being useless, has an important influence in the perception of a quality of tone, and that it acts as a kind of resonator, lengthening the external auditory canal, so as to make certain tones more audi ble than they would otherwise be- It is well known tha. nearly every sound consists of a number of partial tones, and that the number and intensity of these give to our conscious ness the ''color," 'timbre," or ''klang" of that particular sound. These tones are of different pitch-some high, others low. Burnett has found that the peculiar form of the external ear strengthens the higher partial tones By holding the hand behind or around the ear we have the power of adding a still deeper col umn of air and it's resonance to that of the ex- ternal ear. Hence the deaf person involun- tarily places his hand to his ear, to increase by resonance the ordinary sound falling upon it. His hearing is thus strengthened, especially for those tones of high pitch and short wave length to which the human voice owes it's peculiar timbre or klangtint." Helmholtz has already observed in his great work on ''Sensa- tions of Tone :" 'It is, indeed. remarkable that the human voice should be so rich in Over- tones for which the human ear is SO sensa- tive. ."-Good Words.