Depends on how close you are to the speakers as well.
Direct exposure to speakers bigger than you is a contributing factor.
Blame goes to myself for knowing better and continuing to do it.
Interestingly a lot of new starters already show signs of hearing loss, often in one ear. Its generally attributed to MP3 players.
Answer to earlier: Pliny the Elder in 1AD who noted that asbestos workers died young of lung disease. Took nearly 2000 years to get it properly regulated
or Deuteronomy 22:8 When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, if any man fall from thence.
Which just goes to show there's nothing new under the sun