Salt Lake Telegram | 1932-04-28 | Page 4 | Deaf May Hear Sounds with Teeth or Bones

Deaf May lUay Hear Sounds With Teeth or Bones I II I I A new device that brings radio and phonograph music to the deaf not by byway II way ay of the outer and middle ear car passages passages pas pas- sages but through their teeth or the bones of ot their heads has been demonstrated demonstrated demonstrated demon demon- before the National Academy of Sciences by Dr Frederick Bedell physicist of Cornell university Dr Bedell describes his apparatus as a deaf speaker The deaf deat speaker speak speak- er or er however does docs not broadcast sound but carries it directly to the person who holds the receiving part of the apparatus between his teeth or pressed against cheek check bone or fore- fore head To other persons in the same room the apparatus is silent The majority of persons with defective de- de hearing have a defective middle raid mid dle die car ear His aim was to bridge that middle ear and bring the sound waves to the inner ear by some other channeL chan chan- I nel net By means of bone conduction this can be done But it is not enough Dr Bedell found foun in his experiments to transmit vibrations of the same frequency frequency fre ire quency as the actual sound waves themselves to the inner ear of the lis us- tener In order for him to hear through the bones the vibrations must be adjusted to a suitable loudness and force and frequency This adjustment adjustment adjustment adjust adjust- ment is substantially what takes place in the normal middle car ear Dr Bedell's Bedells Bedells Bedell's Be Be- dells dell's deaf speaker achieves the adjustment adjustment ad ad- by stepping up the force of the sound waves and making the amplitude or size of ot the waves smaller Dr Bedell has developed two kinds of oC receiving instruments or applicators s. One kind is held between the teeth and looks like a long tube Theother Theother The Theother other receiver a face applicator is a flat fiat disk to be held against cheek cheekbone cheekbone cheekbone bone or forehead False teeth are no hindrance to hearing with the mouth applicator The disk type of applicator makes H It possible for the listener by means of ofa a microphone to hear his own voice voice This is an advantage to the hard of hearing who rarely are able to know how their own voices sound Tho The apparatus can be used with a microphone for teaching the deaf Dr Bedell reported to la the academy meet- meet Ing The box containing the apparatus apparatus appa appa- ratus is portable but is not small smal enough to be carried on the person for general use I Persons using a telephone often otten use bone conduction without thinking of it when they press the receiver tightly against the ear The bone in front of the ear thus aids in catching the sound It js is possible to hear music on a phonograph record by holding a long needle between the teeth and placing the needle In the grooves of the re revolving revolving revolving re- re cord This shows the princIple prin prin- cIple of bone conduction although i it itis itis is not a n very practical working device de de- de- de vice