552 



BELL SYSTEM TECHNICAL JOURNAL 



10 20 30 40 



HEARING LOSS IN DECIBELS 



60 



Fig. 5 — Percentage of people, both men and women, in the age range 10-59 having 

 a hearing loss greater than any given value. 



TABLE 13 

 Percentage of People Having Hearing Loss of 25 db or More 



etc. without further knowledge of the relation between hearing and 

 the factor in which the group was unusual. 



Accuracy of the Hearing Test 

 The participation of the visitors in the test was entirely voluntary, 

 and nothing is known from the test records concerning their reasons 



