From my experience in examining patients for loss of hearing following injuries to the head, I have come to the conclusion that there is not that constant association between such injuries and loss of hearing which is assumed in the literature on the subject.
This is a preliminary report to determine the functional loss of hearing which follows trauma of the head of varying degrees.
I am defining functional loss of hearing from an industrial angle. Assuming that ordinary conversation is carried on within the frequencies 256, 512, 1024 and 2048 double vibrations, I am basing my deduction on the loss in decibels for these frequencies and calling it functional loss. Sonnenschein1 said:
It is now known that voice sounds range from 200 to 3000 D. V. If an individual can hear low tones below 200 D. V. and high tones above 3000 D. V. but cannot appreciate those frequencies
ROSENTHAL M. "FUNCTIONAL" LOSS OF HEARING FOLLOWING INJURIES TO THE HEADPRELIMINARY REPORT. Arch Otolaryngol. 1939;30(5):775-794. doi:10.1001/archotol.1939.00650060837010