I hate to be preached to as well. My wife has quickly learned that asking me to do something more than once is more likely to extend my procrastination than shorten it. That being said, there are certain scientific facts that can't be ignored.
The time periods vary slightly depending on where you get your data, but the ballpark remains the same. Hearing loss is guaranteed to occur from prolonged exposure and it doesn't take long to add up at high levels.
For anyone who is interested, here are some numbers from a couple of sources. As you can see, some sources are more stringent than others but "beer crushing levels" (luv that term) would rate dangerously high on any scale.
Occupational Safety and Health Administration (OSHA)
85 dB and higher - prolonged exposure will result in hearing loss
90 dBA - no more than 8 hours per day (examples - lawn mower, truck traffic, hair dryer)
95 dBA - no more than 4 hours per day
100 dBA - no more than 2 hours per day (example - chain saw)
105 dBA - no more than 1 hour per day
110 dBA - no more than ½ hour per day
115 dBA - no more than ¼ hour per day (preferably less)
140 dBA - NO EXPOSURE TO IMPACT OR IMPULSE NOISE ABOVE THIS LEVEL (examples - gunshot blast, jet plane at takeoff)
The National Campaign for Hearing Health
85 dB 8-hour period
85 - 90 dB 2-hour period
90 - 100 dB 1 to 2-hour period
100 - 110 between 2 and 15 minutes
110 - 120 less than 30 seconds
130 dB ANY EXPOSURE WILL RESULT IN PERMANENT HEARING LOSS
I'm Riffing. People usually stop me when I'm riffing. Or carry on without me. That's also an option.