high pitch noise in classroom

[MattDLEA]

Last week I got approached by a TA saying that the kids in the hub cover there ears for a minute every so often as there is a really high pitch noise coming from somewhere.

Apparently this has been happening since November but thought to mention it now. I did make the joke about was it the teacher talking.

The problem I have is the noise is at random times and its that high pitched that the teacher, TA and myself cant hear it. There is nothing much electrical in there one computer, connected to a smart TV, an access point and the lights.

Any ideas on what to do?

[korifugi]

Is it just with one class or all classes?

 

If it's one class then I suspect someone is playing sillies.

 

If all - you may have to enlist the youngest member of staff you have (or any trustworthy Sixth Former) for an hour or so to try and track it down

[NB9457]

Not interference from the speakers is it?

 

I've heard PSUs do this in the past. Maybe do it by process of elimination? Swap the computer out for a day or so, ask under what conditions does it happen, is the projector on at the time, the speakers?

[LeMarchand]

I've heard it from PSUs too.

 

Whatever it is, when you find it I'd install it in your office...

[Garacesh]

Speakers. Ground loops.

Dodgy PSU's.

Capacitors in something dieing (happens with our monitors) produce an audible whine, too.

Could be an issue with the lights, if you're using tube lights?

[MattDLEA]

It's just the one room, with it been primary the same class is in there all day.

 

Speakers are built in to the TV so shouldnt be but will turn the sound down as a test.

[Joanne]

I've had an issue with Clevertouch boards making a high pitch noise due to the PSU not being grounded correctly. I had to get engineers in to sort that one out. All covered under warranty.

[elsiegee40]

We had a low energy lightbulb at home that did this. The kids could hear it, but not us so it ended up in our bedroom

[CyberNerd]

Swear I heard on the radio a recent study saying ultrasonic noise can damage hearing, even if we can't hear it. Can't find any reference to it now.

[Joanne]

Swear I heard on the radio a recent study saying ultrasonic noise can damage hearing, even if we can't hear it. Can't find any reference to it now.

 

yep. it's all about the decibels. they did it on Mythbusters but with low frequencies. The speakers were going crazy, but there was no sound. They still had to wear protection though.

 

Edited January 26, 2016 by Joanne

[CyberNerd]

yep. it's all about the decibels. they did it on Mythbusters but with low frequencies. The speakers were going crazy, but there was no sound. They still had to wear protection though.

 

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Thanks- I wasn't sure if I had dreamed it.

So nothing to do with ultrasonic - subsonic in this case.

[Garacesh]

Wasn't that the brown noise episode?

[Joanne]

yes it was.

 

Sorry for derailing the thread OP!

[PyROm]

We have had it before when the charge circuit was dying in the emergency lighting.

[unixman_again]

You haven't got CRT monitors have you? I've known them to squeal and a thump on the side usually fixes it.

[Edu-IT]

You haven't got CRT monitors have you?

For a minute then, I had a flashback!

 

Can the kids point in the direction of the noise?

[dapaulio]

Some of our dink ap whistled. They have all been replaced with unifi ap now

[Max_Power]

We have had a large number of AP's emitting a very high pitched noise every now and again. The AP's still work fine but emit the sound.

 

Teacher cant hear it, but the students also cover their ears as its deafeningly loud.

 

Took it down and gave it a physics / electronics guy see if he could do anything with it and he re soldered a part back on it, but cant remember what the part was, may have been a transistor or something.

[JackCPickup]

Had this with 2 WAPs in a classroom, I could hear it loud and clear but my older colleagues couldn't. Can you swap the WAP for another one?