Re: the word "Bam":

I very much agree with Q that the meaning of this word depends on the context. I believe that 'bam" is an onomapoetic word which is often [?] just the imitation of a sharp, percussive sound [maybe initially it was the sound made by an axe as found in laying track railroad or in chain gang songs?].

Btw,"'Bama" is a whole 'nother word. "Bama" could be an abbreviation for someone who lives in or is from the US state of Alabama. Or it could be part of a nonsense phrase as per the following Little Richard song:

Bama Lama Bama Loo (Richard Penniman)

Bama lama bama loo
Got a girl named Lucinder, we call her the great pretender,
Got a girl named Lucinder, we call her the great pretender,
And when she talks, she says bama lama loo.

Bama lama, bama loo, bama lama, bama loo,
Bama lama, bama loo, bama lama, bama loo,
Now I dig her style, she's like a drive me wild with
Bama lama, bama loo.

I asked my baby for kiss, she shook her head like this,
I asked my little girl for kiss, she shook her head around like this,
She said woooo-oh, yeah.

Bama lama, bama loo, ...
Now I dig that style, its drivin' me wild with
Bama lama, bama loo.

I asked my baby for kiss, ...

Bama lama, bama loo, ...
Now I dig that style, now I'm drivin' her wild with
Bama lama, bama loo.

-snip-
http://www.kolumbus.fi/timrei/lyrics/blbl.html

{I know you guys and gals already knew this. But that gave me an excuse to add that Little Richard song :o)

In the 1960s, I think that "Bang" was the onomapoetic word to beat.
[For example I have fond memories in the 1960s of an uptempo, Latin dance song called "Beep Beep, Bang Bang". But I can't remember who recorded that song-Anybody know?]

But if there were a contest between onomopoetic words that begin with 'b' {such as "Bam"; "Bang"; "Beep", and "Boom", in my opinion, since at least the early 1980s the bass sounding "Boom" would win hands down. Think about "boom boxes", those large portable radio/tape players that were a must-have for teens and young adults if not some older folks. For those radio/tape players "Boom" might have meant that the sound was being loudly projected to folks who really didn't wanna hear it. But I think that in many contemporary R&B, Rap, and Dancehall Reggae songs, the word "boom" often is an approximation of powerful gun fire.

And that's sad and that's scary.