- As far as hearing damage, you still need to have earplugs. You will get less damage with suppressed sound, but it will still occur.
- a standard suppressor like the SilencerCo Harvester EVO put at ear sound at about 136 dB for a 300 Win Mag.
- db is a logrithmic scale. 130 dB is 10 times the loudness of 120 dB, 100 times louder than 110 dB.
- at 110 dB hearing loss is possilble with less than 2 minutes exposure
- at 100 to 1000 times this noise hearing loss can be instantaneous.
while you are correct that you still need hearing protection even with a silencer, but the accepted limit for instant damage seems to be 140db. Below that you can start looking at noise dose, ie time and amplitude of the gunshot. Since gunshot time is between 3.5 and 5 milliseconds it takes a few shots to get your full dose at 136db.
based on what I have researched a single shot at 136db is probably safe. But 10 shots it would be more than a daily dose and ear plugs would be needed.
by the same logic, a single hearing protection like a foam earplug only offers 15-30 db of protection. On a rifle that’s in the 160db range, foam plugs only bring you down to between 140-130, just like a silencer. Still only safe for a couple shots a day. This is why silencers are such a good idea, with both silencers and plugs you are down around 100 db at the ear. At that dose level you can be safe with 100’s of shots.