And Further Proof of How Boring I Am
In the old days, some displays would have these weird telephone receivers on hooks in front of them. They didn't have microphones, only the earpiece. You held it to your ear and listened to a looped recording of a narration. Now, depending on the exhibit, you get a small MP3 player with a number pad on it. Each display has a number on it, and entering that number plays a relevant track. I remember being so fascinated by this I wrote down the name of the company branded on the player. I may have visited the site once, but it was years ago and I've forgotten the name of that specific manufacturer.
However, if they folded, it was likely by competition, because now a simple search for "audio tour" yields a number of service providers. Apparently it's become the norm. It even has a Wikipedia page. It seems a bit sad that a tour guide has been replaced by a machine, but at least it's still a person making the recording, and you're not navigating around herds.
Obviously, this is a very commercial idea, keeping tours as efficient as possible to cut back on crowding and increase turnaround in patronage, but anything that starts commercial can always have an artistic, more personal touch applied to it. It's how any artistic medium starts. I went to the Wikipedia article and found an article under Further Reading entitled, "Speeches of Display: Museum Audioguides by Artists" by Jennifer Fisher. Sounds like exactly what I'm after, I thought.
It is a textbook that costs over 1000USD. The used price is around 200USD.
The individual article, luckily, is only 6USD.