RESULTS OF THE WORLD'S FAIR HEARING TESTS 535 



Fig. 1 — Interior view of one of the hearing test booths. 



opposite the eighth, fifth, and second steps respectively, were intended 

 to give a quaHtative indication of hearing acuity. Thus the visitor 

 could correct his own test and obtain an indication of his hearing 

 acuity for each frequency. 



A scale of hearing acuity for expressing the results of the tests was 

 set up, using as a zero or reference level the mean test score of men and 

 women at the Fairs in the age group 20 to 29. Hearing acuity is 

 expressed as a hearing loss in the usual way, i.e., the departure in db 

 of a given test result from the reference level. As shown in a later 

 section, this reference level gives an ear canal pressure which corre- 



