I recall having seen in the late 1970s or early 1980s an
advertisement/public service announcement, promo, or trailer of some
kind on TV.  This would almost certainly have been network TV, since
we didn't have cable.  Camera was zooming in going up a narrow white
staircase, I believe there was a heartbeat on the soundtrack, and the
camera might have zoomed in on a vent on one of the walls in the
staircase.  I believe there was a voiceover saying something about a
"silent scream."  Visually, that's all it was - camera zooming up a
staircase.

I thought it was possible, and it was also suggested to me, that this
was a trailer for Silent Scream (1980).  However, I watched that on
video recently, and there was not a staircase like that in the movie,
and unfortunately no trailer was included on the video.  For some
reason, I also wonder if it could have been a fire safety promo, or an
antiabortion ad.

Does anyone remember seeing this, and have some more information about
it - ideally some screenshots for confirmation, and maybe information
about where to find a copy of it?