IN TERMS of atmospheric pressure, the ear is sensitive to a variation of 1/12,000 bar. One-millionth of an atmosphere constitutes a bar. The threshold of hearing is lowest for pitches ranging from 2,000 to 5,000 double vibrations. For the same frequencies, the threshold of feeling is also lowest. An intensity of 100 to 200 bars causes pain in this tonal range. The 16 cycle tone is more felt than heard, while a sound of 20,000 double vibrations requires a pressure of 500 bars to be heard. At the extremely high and extremely low tonal zones, the thresholds of hearing and feeling practically merge.
On the audiogram for the normal ear, the level of minimum audibility is indicated by the "zero line." The threshold of feeling is in the intensity range of 110 to 140 decibels for the frequencies 250 to 5,600 cycles per second. Davis and associates1 subdivided the
SALTZMAN M, ERSNER MS. THRESHOLD OF FEELING IN THE FENESTRATED EAR. Arch Otolaryngol. 1950;51(5):667–671. doi:10.1001/archotol.1950.00700020692003
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