I’m sure that someone’s answered this somewhere, but on search of pretty much most of the site (including what forums I could) I haven’t yet seen it answered, so here goes.
What causes the extremely high-pitched whine that comes from a tv or computer monitor screen with the power on? This has been bugging me for years…sometimes the whine is so loud that it gives me headaches, yet my husband claims he has never heard it. So does my dad. My mother acknowledges the sound though she says it has never bothered her to the extent that it troubles me.
Any thoughts? And is there any way I can get rid of this sound?
It comes I beleive from the high frequency horizontal scans at about 15 kHz. As it goes through the electromagnetic could in the tube, these vibrate slightly at this frequency, causing the noise. I don’t know of any way to get rid if it simply
I hate that. When I walk into a house, and the tv is on but the volume is down. Even if it’s a TV in the basement, I always know right away. But know one else can tell. Similarly, often if I walk into a quite store, I can tell if they have security cameras, becuase I can hear the monitor. Yet, I don’t think anyone else in my family can.
I suffer from this too. My Mum and Dad’s TV emits a high pitched whine, or whistle, that no one else seems to hear. Occasionally the TV I have for my PS2 does it too.
There is no solution. The horizontal scanning frequency is 15,750 Hz. Most people hear it initially, but then learn to “tune it out”. I suppose that something could be loose inside the set and be set into motion by this energy, and then begin to vibrate on its own. That might explain an unusually loud whine coming from a particular set.
The specific culprit is a component called the flyback transformer. If it’s particularly loud, it may mean that the flyback is about to pack up. Or it may just continue to whine like that for years. If it’s louder than normal, and really bugged you, I suppose you could get it replaced, but it probably wouldn’t be worth the effort and money.
We have a 12 to 15 year old Sony Trinitron that’s had this problem crop up twice. Both times I took it to the shop and for $75 the tech fixed it. Don’t remember what he said it was, probably exactly what one of these other knowledgable posters referenced, but it was fixable.
Funny story. My high school got its first PC’s back around 1988 to teach a computer literacy class. The computers were installed during the summer. The first day of school that year, we sat down for omputer literacy class. The teacher told everyone to turn on the computers and monitors. Immediately, several students looked like they were in extreme pain and covered their ears. A couple had to leave the room. No one, including the teacher knew what was wrong. Turns out that the monitors that they bought emitted this sound that some people could hear. The sound of 20 of them going all at once was apparently unbearable for them. We were lucky enough to have a few genetic freaks in our class that could hear it. The monitors had to all be sent back and traded in for a less offensive model which took several weeks to do.
Newer TVs put this transformer inside a solid block of plastic, so the noise can’t easily get out. Very old sets had little wooden wedges hammered into the gaps in the flyback transformer to clamp the ceramic half-cores together to prevent vibration, but these get loose.
You might think twice about repairing this yourself, since it’s the lethal part of the TV circuitry.
I think I’ve heard it said that people lose about 1Hz per day from their high-frequency hearing, and we start out at 30KHz or so. That’s about a kilohertz every three years, so you’ll just have to wait, and soon you won’t be able to hear the 15,000Hz whine anymore. And a cheap AM radio will sound just as good as a high-end audiophile system.
I knew I could count on you all to answer this for me. Thanks for all the valuable input! (And I didn’t even have to bother Cecil, which by all accounts is a very good thing.)
Bad news that I have to wait until I’m old to ignore the whine…good news that I’m not crazy or hearing things. Bad news that I can’t fix it myself…good news that I can bug my husband to get us a new set! (Yeah, right.)
When I was younger, I could hear it from anywhere in the house when the TV was turned on. I sometimes wonder if that is why I have always been disinclined to watch TV, although I will if it something I really like. Somewhen between 40 and 50, I realized I was no longer hearing it. Also I started to like violins better.
The standard US TV uses 525 lines per frame (French TV has about 50% more and looks it) and 30 frames per second (actually something like 29.97; does anyone know why?) which means the horizontal flyback transformer runs at 15,750 herz, which is pretty much the average human frequency cutoff (nominally 16 kh, but I think some people go up to 20) and it declines with age. Sounds of that frequency go through most ordinary materials, so I don’t think it would be easy to filter. I wonder if a better insulated transformer might mitigate it though.
My brother was working at a local library when they installed a security system that emmited a high-pitched whine. It bothered him a lot, but no one else could hear it.
And a cheap AM radio will sound just as good as a high-end audiophile system.