Artificial Production of the Heart Sounds
Dr. Leo Jacobsohn, neurologist of Berlin, who is well known for his research on radio technic, has made use of the new sound film to produce artificially human heart sounds. He recently gave a demonstration on the subject before the Berliner Medizinische Gesellschaft. To be sure, the natural heart tones and murmurs have been previously exhibited by means of the radio, as was reported in The Journal, Dec. 26, 1931, page 1977. This method, however, has certain imperfections, which fact gives importance to the experiment of Dr. Jacobsohn, for he uses for the production of heart tones and murmurs no living person, and not even a beating heart, but only a photoelectric cell and a plate marked with vibration records.What is new, in principle, about the method is that the heart tones that are reproduced do not originate in a human being but