We used to have a fancy ass fire alarm system in the 90s and early 2000s. At a couple of points in the house there were detectors, each with a battery, power connected and connected to each other. If one of them detected smoke or heat, they would all start beeping. They would flash every 10 secs to let you know it is in sync, but they would also emit a small beep every 10 mins or so. They never ran out of power since they were connected to mains voltage with a battery backup. The battery was rated to be replaced every 10 years, but I think it was one of those that basically went on forever.
I got used to it after a while, but every now and again I would start noticing the beeps and could not stop noticing them. My dad was proud of them, he paid a lot of money to get them and get them installed.
I lived near a highway and it was so weird when you started hearing it randomly and it wouldn’t go away for 10 minutes. Cars going fast are actually insanely loud.
I recently learned that it’s not the engines or whatever that’s loud. It’s the sound of the tires on the pavement that makes the most of the noise (save for some douche that intentionally made their mufflers loud, obvs)
Yes, that’s why the virtual engine noise generator of EVs only runs until 30kph/20mph before turning off. At that speed the tyres are already loud enough to be audible to pedestrians
I’ve lived in a place with a fire alarm system like that, but the beep is because the backup battery is flat or the unit needs to be replaced.
Most smoke detectors are essentially a small radioactive lump with a Geiger counter next to it; if smoke gets in between it blocks the radiation and if the number of radiation “hits” falls below a threshold in a set time period the alarm goes off. So, as radioactive things have a half life, there’s a point where the radiation emitted falls below the original threshold and you need to replace it. We fucked around with the batteries in ours for ages assuming one of them was low, but eventually replaced the detector itself and the beeping stopped.
Nope these ones did it from the get go. We asked about it when they got installed, it was a feature to let you know they were operating properly. I really to this day don’t know why it was like that.
It wasn’t a loud beep, when the TV was on, you couldn’t even hear it. I only heard it when it was quiet in the house, especially when I wanted to sleep.