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The Symballophone 



homologous areas for differences in duration, pitch and intensity of sound 

 and to discover and localize abnormal sounds. By this method he is unable to 

 detect a lag or delay in motion on one side or in one area although the pal- 

 patory method may be used to detect gross changes in timing. In comparing 

 the qualities of the sounds in different areas, he must remember the sounds 

 heard at one area while he is listening over another. By use of the symballo- 



Fig. 7. Points on the chest at which the two chest pieces of the symballophone may be ap- 

 plied to compare homologous areas. In this manner the respiratory sounds may be compared 

 more accurately on the two sides of the chest. The examination may be completed in approxi- 

 mately one-third the time required when the ordinary stethoscope is employed. Two areas 

 over either lung may be similarly compared. A, ventral view; B, dorsal view of chest. 



phone (fig. 6) two areas may be compared simultaneously. The auscultatory 

 signs in the chest may be examined more quickly and accurately than by the use 

 of the ordinary stethoscope. As shown in the diagram (fig. 7), homologous 

 points may be explored uniformly. Differences in timing of the respiratory 

 movements and differences in pitch and intensity can be readily noted. Locali- 

 zation of abnormal sounds (ronchi, rales) can be determined through laterali- 

 zation. Sounds of different quality may be differentiated in the two areas under 

 observation. The physician with some training may observe a number of differ- 

 ences in respiratory sounds during a single complete respiratory cycle. 



It is well known that the respiratory sounds over the right apex of the lung 

 dorsally are harsh, but it is not so well known that the sounds over the left 

 apex ventrally are harsher. These differences probably are due to the relative 



