Green’s Dictionary of Slang

sound n.

1. (US black) one’s point of view.

[US] in R.S. Gold Jazz Lex. (1964).

2. (US street gang) conversation, talk.

[US]E. De Roo Young Wolves 70: Want sound with you, chum.
[US]E. De Roo Big Rumble 11: ‘Better join, Claw.’ ‘I don’t wanna get involved.’ ‘Don’t gimme no sound.’.
[US]P. Thomas Down These Mean Streets (1970) 54: The next day I was back on the stoop, slinging sound with my boys, yakking about everything we knew about and also what we didn’t.

In compounds

sound boy (n.) (also sound man)

1. (W.I./UK black teen) a sound system operator.

[WI]Chaka Demus [song title] Bad Sound Man.
N. Stolzoff Wake the Town xv: A lot a sound boy a get no sound tonight.
C. Best Roots to Popular Culture 218: Lil’ Rick invokes the Gulf war analogy, at that time a current issue, to declare his superiority over all ‘Hussein sound-boy’.
Jam. Gleaner 5 Nov. 🌐 What is your signature as a sound man?
www.reddit.com/r/hiphopheads Grime Terminology Guide 🌐 Soundboy - Competitors in a sound clash.

2. attrib. use of sense 1.

[WI]Steely & Clevie [song title] Sound Boy Clash.
heading at www.thereggaeshack.co.uk 🌐 Reggae, Dancehall, Ragga n Roots New Releases, Classics, Dub n Rootsman tunes. [...] Sound man buzniz.