Another question asks for the meaning and origin of the phrase "wound [i.e., 'winded'] for sound." The obvious conclusion over there is that "wound for sound" is likely a rhyming variation on the older phrase "wired for sound." There's also general consensus that "wired for sound" at some point had the slang meaning of "high on amphetamines," leading to the modern sense of the word "wired."
Someone on PhraseOrigins points to the Cliff Richard single "Wired for Sound" (1981) and claims it has something to do with portable music players (as in, headphone wires)... but frankly even Cliff Richard's song isn't about portable music in particular. ("I like small speakers, I like tall speakers...")
When the night is clear, and the bombardier
Drops a bomb that's wired for sound,
How I yearn to return, with my head in the clouds,
To the one I love on the ground.
Actually, a Google Books search (which sadly I cannot figure out how to link to, but you can click the search links at the bottom of the Ngram Viewer page) shows pretty conclusively that the phrase comes from movie theaters being "wired for sound", as in "having wiring installed for the purpose of playing talking pictures." Which I think means I've answered half of my own question.
The other half is, what was the original slang meaning of "wired for sound", such as in the song lyrics above? In that context, does it just mean "a bomb that explodes loudly," with a subtle positive connotation toward modern technology? or was there a more specific meaning that 1940s audiences would have picked up on?