Abstracts of Bell System Technical Papers Not Published in This Journal (01 September 1952)

Operational Study of a Highway Mobile Telephone System. L. A. Trans. A.I.U.K., 70, Part 1, pp. 3 1 - 3 7 , 1951. (Monograph The Dynamics of the Middle Ear and Its Relation to the Acuity of Hearing. H. FLETCHER1. J. Acoust. Soc. Am., 24, pp. 129-131, March, 1952. The transformer action of the middle ear as measured by Bek6sy is shown to be the principal cause for the low acuity of hearing for low frequencies. 

Because of the very low mechanical impedance across the basilar membrane at low frequencies, large acoustical pressures in front of the ear drum produce appreciable acoustical pressures across the basilar membrane. For example, at 100 cps this pressure is thirty times and at 6000 cps it is one-tenth that created across the basilar membrane.