>. . . Visitors love these . . . and they are understandably
>frustrated when they cannot understand the sound tracks, whether because they
>have hearing losses or because of noise in the area.
>
> . . . it's a matter of making materials more useful for everyone and of
>allowing people with hearing impairments to get the benefit of materials that
>are accessible to others. . . .
> David A. Penney
> Exhibitions Manager
> The Baltimore Museum of Art

 There is another option besides screen captions and the closed captioning
already mentioned:
Ontario Science Centre (Toronto, Canada), has started using "super title" -
like text displays to provide captioning for spoken dialogue of videos.
(Some might have seen the supertitle technology in opera houses providing
simulataneous english translations of what is being sung)

The lighted dot unit they use is about the size of a large ruler with
running text display. This strip is set up seperately below the video
monitor - both encased in plexi box.  I think both are plugged into a
controller unit but an OSC staff person would  be a better reference than
me.

I believe the video has to be transferred to laser disc or computer hard
disc so that the words can be "triggered" to synchronize with the screen
action.  Check with them if you are curious to find out the technical
details of how they did it, expense involved, and how well they think it
works.

Claire Pillsbury