Popular Science Monthly 



353 



Helping the Deaf to Hear with a New 

 Electrical Ear 



ANEW instrument to help the hearing 

 of the deaf is so constructed that 

 buzzing and grating sounds are entirely 

 sifted out. The sounds received are 

 actually increased in volume so that 

 practically every partially deaf 

 person can hear with its aid. The 

 clearing of the tone is accom 

 plished by carrying the sound- 

 waves through the receiving 

 mechanism in much the 

 same way that a stream 

 of water is sprayed out by 

 the presence of a button 

 in the middle of the nozzle. 

 Hence the sound does not 

 bound out of the instru- 

 ment, but is carried 

 around and thrown back 

 on the diaphram of the 

 microphone, after all 

 rumblings have been lost 

 in the steel passages correspond 

 ing to the auditory^ canals of the 

 normal ear. 



The magnifying of the sound depends 

 on the drum-head or sounding board which 

 is buried in the heart of the instrument. 

 The sound, after entering, is carried around 

 through the sound chambers. It strikes on 

 the curved surface of the drum-head, from 

 which it is deflected through a perforated 

 screen to the diaphram of the microphone. 

 The drum-head is made in varying degrees 

 of curvature, and of different materials and 

 thicknesses. 



The makers of the instrument have also 

 prepared a testing system, not unlike an 

 optician's test case, by which a physician 

 can determine exactly, not only the proper 

 curvature and thickness of the drum-head, 

 but also the material of which it should 

 be made. This varies from brass to lead, 

 with silver, rubber and glass in the list. It 

 has been found that the material gives the 

 quality which is vital in getting just the 

 pitch which will affect what sense of hearing 

 is left. It is claimed that 

 by careful fitting, as to 

 form and material, in 

 the drum-head, the deaf 

 person can be made to 

 hear nearly all words 

 and sounds in their 

 natural tone. 



The new instrument is 

 the product of the in- 



AIR 5PACE 



SOUND ENTERS 



Above: The electrical 

 ear, showing how the 

 magnifying of the 

 sound is accomplished 

 by the drum-head 



The transmitter is 

 easily concealed in the 

 clothes and the ear 

 disk is reduced to a 

 very small diameter 



ventors who perfected the 

 wire-tapping telephone in- 

 strument which figured so 

 prominently in the news a few 

 months ago, and they have 

 adapted to the perfection of 

 the new ear-phone the same principles 

 which made the "listening in" inaudible. 

 Heretofore, electrical manipulation and 

 tuning have been the only means of increas- 

 ing the efificiency of the microphone, but 

 with the new ear-phone, this electrical 

 adjustment is aided in its work by the 

 ingenious mechanical developments of the 

 drum-head and the open spaces inside the 

 instrument. 



The disk that goes to the ear is reduced 

 to a diameter of an inch and one half, 

 and the transmitter, three inches in diam- 

 eter, is easily concealed in the clothing. 



A New Pipe Which Is Sanitary 

 and Nicotine-Proof 



PIPE smokers are ever on the alert for a 

 pipe which is nicotine-proof. The dis- 

 advantage with pipes which claim to live 

 up to this feature is that they cannot be 



cleaned readilv 



CENTER HOLE BURNS EVENLY 

 EASY TO CLEAN 



NO MOISTURE PASSES HERE 

 PATH OF SMOKE aEAR 

 THE CLEAN WELL 



The internal construction of the 

 pipe, showing the cleaning well 

 and the path the smoke takes 



They clog up with small 

 particles of tobacco. 



The pipe illustrated 

 can be cleaned whenever 

 the smoker wishes. Fur- 

 thermore, nicotine can 

 not be drawn through the 

 stem, since the stem is 

 disconnected, allowing 

 all moisture to drip into 

 an easily cleaned well. 



