I used to fire the swedish Carl-gustav before beeing upgraded to At4(end of cold ware- no more real rounds). I remember it as having the same specifications and rounds/rockets as the AT4 (except from reloads).
I like to add that that with the standard hearing protection 'plugs', it takes a couple of minutes before the ringing goes away.
It's not the sound that get's in your ears but the pressure wave comming from the initial kick-out charge. The shape of the blast wave is designed to give the crew the lowest impact (if you remember to keep your mouth open). Any by-standers are in for the real shock/noise.
I remember that when used from a trench, the safty distance (side way's was 8 meters. To give you all a clue on the force, I remember a firering execise with the old type gas-mask and a winter cold. After the first shot, there was no problems breathing. But looking out the mask, was a big no go .
The real problem in the old days when soldiers was not allowed to carry any sun classes. The problem with the recoilless rockets, was that when the rocket gets 10-20 meters down range the rocket engine ignites. If you was so careless to let go of the sight and try a direct look, you would have sand and dust kicked in your eys.