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A few years back I had a monitor at work where I complained to my boss that it was emitting a high pitched whine. I was about 10 years younger than anyone else

A few years back I had a monitor at work where I complained to my boss that it was emitting a high pitched whine. I was about 10 years younger than anyone else on the team, and no one else could hear it. The PC technician I called to look at it couldn't hear it. Needless to say it didn't get replaced, that is until we got a summer intern. The first time the intern walked past my desk she asked "how can you stand that sound?" and I had her go to my boss to say the same thing. My boss got another intern from another team to listen and confirm, and I got a replacement the next week. It's one of those sounds you can never drown out, it's such a unique frequency.

SilasX 9y ago
Advice for next time: you don't have to depend on a human's word. You can use a real-time analyzer [1], now available in smartphone apps. They display the frequency spectrum of ambient noise. We had a similar situation at our office, were the smoke detector was emitting a steady whine that only a few employees (including me) could hear. One skeptic was finally convinced by getting out an RTA app and seeing the big spike at 12 kHz. [1] https://en.wikipedia.org/wiki/Real-time_analyzer https://en.wikipedia.org/wiki/Real-time_analyzer
- aoeusnth1 9y ago
  Wow, 12 kHz is not audible to most adults? That's pretty surprising.
  - SilasX 9y ago
    I don't know the percentiles by age (it's hard to find from googling). Just saying that that one fortysomething adult couldn't hear it.
  - tripzilch 9y ago
    When I checked this, as a fun experiment to do with kids (they love "winning" this game, after all), is that yes while I'm technically able to hear 15-16 kHz, there's a very steep drop-off in sensitivity already quite a bit below that. I needed to turn up the volume on a pure sine-wave quite high (which the kids hated immediately) to be able to hear it somewhat clearly. So if you add in ambient noise (in lower frequencies), that could plausibly drown out a 12 kHz noise very well, for older adults (I'm mid 30s myself). Interesting side-note: Turns out that the low end drop-off (at about 20-25 Hz or so) is not very age-dependent at all (at least when I tested these "against" a 13-year old's hearing). You need quality headphones for this, most speakers will distort/resonate some higher frequency harmonics, which you can always clearly hear. It was very interesting to hear something that was clearly a very very low frequency tone turn into a sort of rapidly fluttering/beating sensation at the cross-over frequency, you can feel it beating slightly on your eardrums, but it doesn't translate into a "tone-like" sensation any more. And yes we made sure to not do it for more than a few seconds, to not accidentally cause hearing damage--though with good closed headphones we didn't need to turn it that high, as the effect wasn't so much that the perception of the tone "disappeared", rather change into a different type of sensation.
ogn3rd 9y ago
Should have tried changing the refresh rate.

SilasX 9y ago

Advice for next time: you don't have to depend on a human's word. You can use a real-time analyzer [1], now available in smartphone apps. They display the frequency spectrum of ambient noise. We had a similar situation at our office, were the smoke detector was emitting a steady whine that only a few employees (including me) could hear. One skeptic was finally convinced by getting out an RTA app and seeing the big spike at 12 kHz. [1] https://en.wikipedia.org/wiki/Real-time_analyzer https://en.wikipedia.org/wiki/Real-time_analyzer

aoeusnth1 9y ago
Wow, 12 kHz is not audible to most adults? That's pretty surprising.
- SilasX 9y ago
  I don't know the percentiles by age (it's hard to find from googling). Just saying that that one fortysomething adult couldn't hear it.
- tripzilch 9y ago
  When I checked this, as a fun experiment to do with kids (they love "winning" this game, after all), is that yes while I'm technically able to hear 15-16 kHz, there's a very steep drop-off in sensitivity already quite a bit below that. I needed to turn up the volume on a pure sine-wave quite high (which the kids hated immediately) to be able to hear it somewhat clearly. So if you add in ambient noise (in lower frequencies), that could plausibly drown out a 12 kHz noise very well, for older adults (I'm mid 30s myself). Interesting side-note: Turns out that the low end drop-off (at about 20-25 Hz or so) is not very age-dependent at all (at least when I tested these "against" a 13-year old's hearing). You need quality headphones for this, most speakers will distort/resonate some higher frequency harmonics, which you can always clearly hear. It was very interesting to hear something that was clearly a very very low frequency tone turn into a sort of rapidly fluttering/beating sensation at the cross-over frequency, you can feel it beating slightly on your eardrums, but it doesn't translate into a "tone-like" sensation any more. And yes we made sure to not do it for more than a few seconds, to not accidentally cause hearing damage--though with good closed headphones we didn't need to turn it that high, as the effect wasn't so much that the perception of the tone "disappeared", rather change into a different type of sensation.

ogn3rd 9y ago

Should have tried changing the refresh rate.