They're wind chimes. I know most people like to tie little prayer flags and scarves and stuff to the air-vent to make sure it's working, but back home we use wind chimes. You don't have to be looking at 'em to know they're working.
They're not like the chimes they have back on Earth; these only have one note. Most habs around Saturn do it that way – each compartment has a single note. That way, you can tell location of a faulty blower just by the change in the sound. And let me tell you, they are not optional. If you take a set down for anything other than maintenance on the air-vent in question, you can get arrested.
Of course they're loud! That's how you know they're working. But I know what you mean – when I first moved out to Titan, it took me a good month to get used to 'em. I was up all night most nights hearing chimes all over the hab ringing. It was like this constant drone with a few off notes every now and then to make sure you didn't relax. I complained to anybody who'd listen, which was nobody. All I did was get myself a rep as another dumb groundhog fresh off the boat
The chimes didn't just bother me at night, either. They are everywhere. In public spaces they make quiet conversation just about impossible. And I just about failed my first semester in school from being distracted. I tried to use noise-canceling ear buds during study hall one time and almost got expelled for “negligence and reckless endangerment”. Seriously, if I hadn't still been under Immigrant's Probation, I would have had to do a public service sentence. I thought that was crazy – or some kind of bullshit hazing for the Earthworms or something. As it was, I did have to take the Habitat Orientation class again – listening to the damned wind chimes the whole time.
But let me tell you – They were absolutely right to bust me. They confiscated my ear buds when I got caught so I didn't have them during a weekend maintenance cycle on the hab. We were living in a retired Trans-Chronian, the kind they used to have before the River-class came out. The counter-spinning rings were always breaking down or getting fatigued or some damn thing, so we only had gravity maybe five days a week. My little sisters loved it – I'd play catch with them, with the toddler standing in as the ball. Anyway, the apartment had only pair of rooms, and my parents got one and the girls the other. I slept in a bag in the living room and lived out of a foot locker. One night I woke up from a dead sleep with the uncontrollable feeling that something was wrong. I couldn't put my finger out what it was, but the effect was disturbing. I figured that I was just having trouble sleeping from the wind chimes when I realized that was what was wrong – I wasn't hearing the chimes.
A glance up told me that the chimes in the living room were still going, but I really didn't need it. The sound of all the chimes in our apartment had gotten so far under my skin over the weeks we'd been living there that I pretty much figured out immediately which chimes had stopped. You guessed it – the girls' room. By the time I got in there they were both awake and holding hands while spinning like they teach you. My parents were in there a couple seconds after me, but only because they had farther to go.
Anyway, it was nothing much as vent problems go. A stuffed rabbit toy had gotten jammed into the fan – so the girls got grounded and had to do extra chores for a week. They whined about it, and kids do, and then we all went back to bed. It took a me good while to go back to sleep after that. For all I my complaining about those annoying, distracting, aggravating wind chimes, if we didn't have 'em up that night my sisters would have never have woken up. Ever again.
So, you don't mind me hanging these up, do you?