https://taimuihonghue21.files.wordpress.com/2010/08/occupational-hearing-loss.pdf
823-825
"Q. What about in the area of progression or non-progression, anything characteristic in terms of long-term noise-induced hearing loss? A. It generally continues to progress.

Q. What if an individual is removed from the noisy environment, does it continue to progress ?
A. It may, yes."
The American Occupational Medicine Association (AOMA) Committee defined occupational noise-induced hearing loss as a slowly developing hearing loss over a long time period (several years) as the result of exposure to continuous or intermittent loud noise. PAGES 414-415