Observations on the conservation of hearing

Longitudinal Study of Human Hearings: Its Relationship to Noise and Other Factors. 3. Results from the First Five Years

“…These analyses show that when more data become available during the continuation of the study, and when more complex curve fitting techniques are applied to longer runs of serial data, it is reasonable to expect significant contributions will be made to understanding the development of hearing abilities in children and the quantitative effects of environmental noise and other factors on the hearing abilities and communication of children. Newhart (1940), using pure-tone audiometry, studied 6,344 children in Minneapolis and found significant increases in thresholds in 5.4%. Ciocco and Palmer (1941) studied 13,982 school children in Washington, D.C.…”