The example of the poetry reading reminded me of two things:
1 - If the performer(s) is made aware (or asked), that can help them. If the performer(s) asked you to be there, that is all that matters.
2 - Many performers are used to distractions, and a camera may actually be less annoying than other sounds at the venue.
The audience, however, may not be used to these things.
An idea that might help you gauge the concept would be to visit a local council meeting. Don't pay attention to the meeting, pay attention to the "audience." Do the same at a local church service - even if you are not religious. Simply being there won't bother anyone so long as you are respectful (and they likely will not know so long as you act like they do). Maybe find a coffee shop that sponsors poetry readings and listen there as well.
Speaking of church, perhaps I'm a bit irreverent, but at my father's funeral service, I was commenting to my mom how ugly they painted the inside of the church since I was last there. I whispered, so only my mom knew what I was saying, but people could tell I was whispering. Meanwhile, I kept hearing coughs, bumping kneelers, coat and purse zippers, whispers, and hushed voices telling very young children to be quiet. Nothing really out of the ordinary for that venue. If I heard a camera, I might think it odd, but it would not have been any more distracting.
When you get a group of people together for anything, various "noises" are common.
Dull thuds and whisper-level sounds are usually not so distracting. Loud bangs or something just below normal talking voices are. I'd rate a "loud" shutter and manual winding as a dull thud, and a motor drive (at least the ones I've heard) as just below talking level.