ChainsawAsh said:

My guess is it's someone reading the crawl aloud to their child in the theater (my parents did this for my brother in 1997 when we saw the SE in theaters - they did it for the alien subtitles, as well).

I haven't listened to this recording, so that's only a guess.

The voice sounds almost robotic. Either that was in the opening crawl in the 1977 version, the guy added it himself, or it was possibly someone reading it out loud to their kid like you said. Hopefully he can clarify when he gets a chance.