Hörempfindungen im Ultraschallgebiet

Tones between 15 and 200 kcycles are audible when applied by bone-conduction. The resulting sensation is to be observed not over the whole surface of the head and neck, but only over many points, of which early 60 have been investigated in cases of normally hearing persons of both sexes and middle age. The sensation is that of a very high tone and does not change according to frequency. The highest limit of hearing may lie near 200 kcycles. The reasons are discussed why hearing in this “ultrasonic” range seems to be a real one, which can be understood by observations ofGalambos andDavis on single nerve fiber-preparations.