@aba

I have spent some time reading online Journals of Audiology, Otolaryngology, Hearing etc and there have been decades of studies related to Noise Induced Hearing Loss (NIHL). Many of the studies I read were pertinent to a particular group of people according to their occupation, for example Firefighters. NIHL is a complex disease and any resulting loss can be result of many factors, such as the intensity and duration of the noise, genetics and age. This is why the debate as to whether any loss is ongoing, gets worse or is permanent is still ongoing. There are some conclusions that seem to be agreed on...for example, noise trauma seems to affect the left ear rather than the right and some people seem to be more predisposed to noise damage than others. (genetics).

You won't find your answer here . I suggest you might want to do your own research for more in depth answers. This is not an easy subject and you know studies contradict each other. Many of the scientific terms and explanations I came across were out of my depth. What everyone posted here is general, useful knowledge. We hear your frustration and I hope you will share anything you come across.

FL Mary