How loud is the M4 and M16 and AK-47 are they both equally loud?

If the M4 is nothing but a shorter version (carbine) of the M16 jungle rifle (assault rifle), then it'll be abit louder for the rifleman; example: when firing the same indentical .22 cartridge's (a cartridge from the same 50 round box), a .22 caliber pistol will hurt your ears, but a .22 caliber rifle will NOT hurt your ears. Another words, if the shooter places one .22 round into a pistol and fires it, it'll hurt his ears, when he takes out the second round from the very same box of ammo and loads it into a rifle, it won't hurt his ears. Shorter barrels are louder.

The M16 was designed for jungle warfare; that is to say, throwing lead fast in great amounts (as GIs in Vietnam sometimes stated, "spray and pray"). In South Vietnam, jungle vines, leafs, branches, etc. were often TOUCHING your rifle's barrel, magazine, or trigger housing. Visibility was zero, the only thing in front of you was leafs and branches and vines, so when you fired your "jungle rifle" all those leafs, vines, and branches blew out of the way like a shotgun blast blew them away. If you fired an M14 rifle thru the brush, if seemed like you were firing BLANKS, the jungle was still there! So the fast firing M16 was much more psychologically comforting than the M14 rifle was. The M16's bullet fired so fast, over 3,000 fps, that they sounded like a sharp crack, definitely HURTING your ears when fired.

AK's seemed to fire more slowly, seemingly sluggish like, they had a low "crack" to them, more like a "bang". When the NVA fired their AK's and GI' returned fire with their M16's, you could definitely tell which party of men were where. Even their Chicom stick grenades sounded differently; US grenades went off with a tremendous roar (like a 60mm mortar round); chicom grenades went off with a simple "pop."

The next time you cook up a batch of popcorn, and they start popping...that's about what a typical Vietnam firefight sounded like, without the grenades and mortars going off.