4 ms·

I can hear a local FM radio station if the room is quiet but a fan is blowing air. At first I thought it was just one fan that did it, but it seems to be almost

by NikkiA 3y ago

I can hear a local FM radio station if the room is quiet but a fan is blowing air. At first I thought it was just one fan that did it, but it seems to be almost any fan. Most of the time what I can hear is just at the edge of my hearing, but the past few weeks it's been loud enough to occasionally ID songs that are playing (they play 'Paradise City' and 'Living on a prayer' quite often, which are very easily ID'ed because of non-language vocals in them - ie the 'Oooooh' parts). I figure that the fact that the antenna is about 500m away is probably a good portion of the reason it's audible, but whether it's actually acoustically audible, or just RF that I'm pseudo-hearing, I don't know. I used to logically assume that when people could 'hear' radio it was only possible with AM because FM modulation shouldn't be demodulated in resonant cavities like AM is, but this station has no AM presence, only FM and DAB.

steve1977 3y ago
And you can rule out it’s not some neighbor listening to that station?
- NikkiA 3y ago
  Not conclusively, I guess, but it's there at any time the conditions are correct (ie, a fan moving air somewhere in the apartment, and otherwise silence). It, however, sounds nothing like an acoustic leakage sounds, I'd describe it more as envelope-shaped white noise then filtered to a range of 'high' acoustic frequencies (maybe 8-14kHz, but I'm guessing); whereas structural leakage of audio has a different profile more in line with being low pass filtered. I have heard leakage audio from the only neighbour that it COULD be from, of their TV and Radio audio, and that has the normal low-pass sounding profile as you'd expect. So while I can't rule out that it could be leaked audio, it 'doesn't sound like it' to me.
  - blincoln 3y ago
    I grew up in a house that was next door to a radio rebroadcasting facility, and we could definitely hear the radio station coming from the walls of our house sometimes, e.g. even their station identification so there was no ambiguity. I assumed it was the house wiring (mostly knob and tube) acting as an antenna. I'm reasonably sure that was AM, though. Was the sound you heard like either of these? https://www.youtube.com/watch?v=uo9nGzIzSPw https://www.youtube.com/watch?v=uo9nGzIzSPw https://www.youtube.com/watch?v=b9UO9tn4MpI https://www.youtube.com/watch?v=b9UO9tn4MpI

by NikkiA 3y ago

steve1977 3y ago

And you can rule out it’s not some neighbor listening to that station?

NikkiA 3y ago
Not conclusively, I guess, but it's there at any time the conditions are correct (ie, a fan moving air somewhere in the apartment, and otherwise silence). It, however, sounds nothing like an acoustic leakage sounds, I'd describe it more as envelope-shaped white noise then filtered to a range of 'high' acoustic frequencies (maybe 8-14kHz, but I'm guessing); whereas structural leakage of audio has a different profile more in line with being low pass filtered. I have heard leakage audio from the only neighbour that it COULD be from, of their TV and Radio audio, and that has the normal low-pass sounding profile as you'd expect. So while I can't rule out that it could be leaked audio, it 'doesn't sound like it' to me.
- blincoln 3y ago
  I grew up in a house that was next door to a radio rebroadcasting facility, and we could definitely hear the radio station coming from the walls of our house sometimes, e.g. even their station identification so there was no ambiguity. I assumed it was the house wiring (mostly knob and tube) acting as an antenna. I'm reasonably sure that was AM, though. Was the sound you heard like either of these? https://www.youtube.com/watch?v=uo9nGzIzSPw https://www.youtube.com/watch?v=uo9nGzIzSPw https://www.youtube.com/watch?v=b9UO9tn4MpI https://www.youtube.com/watch?v=b9UO9tn4MpI