Comment by Syonyk
5 years ago
> I have very acute high-frequency hearing...
Doesn't take "acute," just takes "not destroyed."
I've, at various points in my career, grumbled about various things whining audibly (one particular motion light sensor was defective and right outside my office for a while). The trick to getting other people to believe you ("I can't hear anything... are you sure?") is to wait for a bring-your-kids-to-work day. And ask if they can hear it.
Or, perhaps, if it's bad enough, you don't even have to do that, because the kids will ask what that horrid whining noise is. We did eventually get it fixed after that, but I was quite literally the only one in the hall who could hear it.
On the topic of power supplies, though - Apple has done some impressive work in their small power supplies. The Chinesium clones are similarly sized, they just skip literally every safety feature intended to keep mains voltage out of your USB cord...
> On the topic of power supplies, though - Apple has done some impressive work in their small power supplies.
And a nice teardown is done here, by the same guy: http://www.righto.com/2015/11/macbook-charger-teardown-surpr...
> Doesn't take "acute," just takes "not destroyed."
It depends. Played in an orchestra, and I've found out that hearing is very different from person to person. Seen people with hearing lower than 20Hz band, or people who can hear a wrong note in a symphony orchestra recording, or people who can perfectly tune their instruments by ear... The list goes on and on.
Our ears' equalizers are not always flat and equal. We can damage them yes, but not everyone starts from the same point.
> Seen people with hearing lower than 20Hz band
This is called subsonic hearing, and it is not any blessing. Those who can hear frequencies lower than most often experience pain. It's the low frequencies coming from diesel school busses that are most painful to me, when no one else nearby can even hear the bus at all until it gets close enough. What the GGP is talking about is supersonic hearing, which often also includes that extra detail of pain.
Gotta hand it to the kids. My 9 year old claims he can hear a whine from iPads and iPhones when their battery level is near 0%. And I thought I had good hearing...
Oh I believe it, when I was young I could tell if CRTs were powered on (even if the screen was black) just due to their whine.