I'm not sure I understand what this would accomplish. Quiet atmosphere for isolated slideshows? Why wouldn't everyone viewing the slideshow be just as vulnerable?
But the people viewing the slideshow are the ones that are -supposed- to be hearing the audio.
I actually think this technology can be useful in some ways. Imagine it this way - picture yourself in a museum - a place it's generally supposed to be very quiet. When you stand in front of an exhibit, the requisite audio plays for you, and only you (and whomever else is standing in front of that particular exhibit) - it's not just blaring out into the hall. In other words, if I'm standing in front of a wall explaining the discovery of Australopithecus, I don't want to be hearing audio from the geologic strata exhibit on the other end of the hall; I want to hear THAT audio only when I'm at THAT exhibit.
Many museums these days have a station with one or two sets of earphones, which accomplish the same thing, but are uncomfortable. Plus, in order to learn anything, you've got to wait until the person in front of you is done listening first; and in my experience in museums, NOBODY hangs around and waits - they just skip that exhibit and move to something else. That kind of defeats the purpose of having that exhibit on display. Sometimes, even when nobody is there, patrons just don't pick up the earphones and listen. Why are they even there?
Also available these days - usually for a fee - are tape-recorded "guided tours", wherein you carry a personal tape player with earphones, and you're expected to keep up as the audio narrator moves around the museum. I've noticed that people get lost wearing these - they find themselves in the middle of a hall with no idea of what exhibit they're supposed to be looking at next.
But outside of this circumstance, I can't see that this technology can be good. Schizophrenia just doesn't seem like a proper selling tactic to me.