150 decibels is way past the threshold for phsyical pain and will permanently damage your hearing. The device the nyc cops have purchased is a focussable sound beam. It can hurt you without hurting them. They can aim it. It will not diminish in volume at the same rate as normal sound. In short, they can permanently deafen you and then go for donuts.
At guitar center, one can purchase extremely cheesy earplugs actually called sound filters. I wish I could tell you the brand name. The rating on the back for how much sound they block is extrmely poor. The packaging claims that they respond to sound levels. Tests are done at very low levels so they block out only low levels of sounds. the packaging claims that in a firing range, those little sound filters work almost as well as the big earmuffs that shooters wear. A gunshot is only 140 decibles. At that lower volume, "any length of exposure is dangerous; noise at 140dB may cause actual pain in the ear." This thing is ten decibels louder. The cops in nyc want the ability to make all protesters go permanently deaf.
Theoretically, things like pepper spray, tear gas, rubber bullets, whatever are supposed to do no permanent harm. this is not the case with these devices. They will maim people for the rest of their lives. the police claim they're not going to turn them up that loud. Why do they even have them? Why would they have a weapon and not use it? It's illogical that they would purchase somethign with those capabilities with no intent to actually put them to use. If that was the case, why not diable the higher volumes?
In short, protect yourself from the pigs by getting ear protection. They have two of these things and plan " to mount them on Humvees posted outside Madison Square Garden." You won't hear it until it's too late. I say, if you're near there, you ought to be protecting your ears. 33 db reduction isn't much, but it's better than nothing. Or order 40+ db protection from germany 110 db is "safe" for a short period of time, less than half an hour, but that's better than nothing.