Speakers for High Frequency Sound

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

> Interestingly, your cochlea can hear tremendously high
> frequencies well into "ultrasound" above 20 kHz, so long
> as they are gotten in by bone conduction (putting the
> transducer on your skull). It's the earbones that are the
> block. Perhaps there are some people who have
> particularly good skull connections to their inner ear.

I have a theory that my sinuses might have something to do with it. My
sinus cavities on the front of my face are fairly small, but I know
that I have more sinus cavities farther along the roof of my head. I
also suffer from TMJ, and the pain in one jaw joint is bad enough that
I often can't sleep on that side. So, maybe the internal structure of
my skull explains how I hear this sound, and my sinus and jaw problems.

 

[marc]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

<pooua@aol.com> wrote in message
news:1108170172.822645.33210@c13g2000cwb.googlegroups.com...
> My objectives are to find out what frequencies I can hear, and to match
> one of the calibrated frequencies from the signal generator against the
> sound I hear from televisions, so that I can finally know what that
> frequency from the television is.
>
> I am certain that just about any commercial audio signal generator is
> going to be callibrated well enough to distinguish the frequency I
> hear. It isn't that difficult to make a stable signal (particularly in
> commercial test equipment, which is what the signal generator is).
>
> As for how much I would spend, well, I can justify some of the expense
> because I am an electronics hobbiest. So, I don't mind buying a $200
> piece of test equipment as much as I might otherwise. And, I am going
> deaf, so I don't have forever to make this test.

You won't need your hearing to do this test all you need to do is turn on
the tv
and have the proper measurement equipment and a pair of eyes to see the
results
on your equipment.
So there's no hurry.

>
> But, this is nothing. I would spend over a thousand dollars to test
> some of the other things about myself that I want to test. In
> particular, I can generate a sensation like electricity throughout my
> body, at will. I don't know what that is, but I would like to find out.
> As in, I would spend a thousand dollars to find out.
>

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

FWIW, I can hear computer monitors, too, but not as well as
televisions. That's a good thing, because I work in an office with a
hundred computer monitors. The room has to be quiet and I have to pay
attention for me to hear a computer monitor, unless it is going bad.

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

> > Some people can hear an extremely high-pitched sound generated by
> > television CRTs and television cameras.

> When they're badly designed / manufactured - yes.

I have never met a functioning CRT that I could not easily hear.

> Incidentally, I just got my hearing checked by my ENT (Ear, Nose,
> Throat doctor). I measured in the 5-to-10 dB range on both the
eardrum
> and nerve conduction tests across the entire measured frequency range
> (up to 8 kHz for eardrum, 12 kHz for nerve conduction). My doctor
said
> that they want to see values less than 20 dB, so I am well-within the
> safe zone, as far as they are concerned. However, one reason that she
> scheduled this test for me is that I complained that I am going deaf
in
> one of my ears. I have almost completely lost my sensitivity to the
> ultra-high pitched sound in that ear. I can hear that sound 100 times
> better from my other ear.

> Well - I had a proper hearing test when I was in my mid 20s and the
nurse
> commented that I had the most perfect hearing she'd ever measured.

> I was on the 0dB line all the way to 8 kHz - the highest frequency
used for
> medical testing it seems.

8 kHz is the max for headphone tests of the eardrum.
12 kHz is the max for nerve conduction (through the skull).

> > Other people can hold a conversation in a normal
> > voice, but I have to listen over a sound similar to a dentist's
drill
> > or a jet engine. After several minutes of that, I often feel dazed.
No
> > one else even notices anything, except maybe that I am acting a
little
> > more odd than normal.

> You mean you have diffiiculty with large background levels of noise ?

> Can't 'reject' it ?

There is a limit to what anyone could reject. As I say, the sound is
similar to the sound of a dentist drill or a jet engine, not just in
pitch, but in volume. This is not a subtle effect.

> Me too. You have high hearing acuity. Your ears are 'wide open' to
stimuli.
> May ppl simply 'filter out' what they're uninterested in.

If I watch TV, I often tune out the sound of the TV. Then, again, the
sound is louder when there no picture displayed. In fact, I can hear
shifts in pitch and volume as a television changes the image it
displays, or if it has trouble locking onto an image.

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

<pooua@aol.com> wrote in message
news:1108169534.239460.145530@z14g2000cwz.googlegroups.com
>> It's the horizontal scanning frequency, 15,734.25 Hz for American
>> color TV. Trust me. You don't need to measure it.
>
> I need to measure it, to be certain that is what I am hearing.
>
>> If humans can hear it, it can't possibly be at 40kHz, because
>> the best human hearing extends to only a bit above 20kHz.
>
> I think you are assuming some things that aren't necessarily so. One
> very important assumption you are making that is likely to be wrong is
> that no human can hear very much above 20 kHz.

Yes and no. If the intensity is high enough, it may be possible to discern
pure tones above 20 KHz. OTOH, hearing the removal of sounds is a different
question, and the borderline frequency for most people is around 16 KHz.

> There are a number of ways that assumption could be wrong.

There are a probably an infinite number of ways that any assumption could
be wrong, but that sheds little light on whether the assumption is correct
or not.

> In any event, there is no
> physical mechanism that would prevent a human from hearing higher
> frequencies.

Sure there is. The perception of pitch is based on the activation of hairs
in a coil-shaped structure in the ear. The finest hairs relate to high
frequencies, but they don't go on forever. Basically, you run out of
structure at some point in this part of the ear, and the extent and health
of this structure sets the highest frequencies that you can perceive. It's
not uncommon for this structure to be damaged by listening to excessively
loud sounds.

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

> So, anyone up for a controlled experiment?

I'm game, provided the experiment is within reason. I can't quit my job
or spend a day out of town, or anything like that (OK, I might be able
to manage the day out of town).

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

William Sommerwerck wrote:
>>Some people can hear an extremely high-pitched sound generated by
>>television CRTs and television cameras. I have long wondered what
>>frequency this sound is.
>
>
> It's the horizontal scanning frequency, 15,734.25 Hz for American color TV.
> Trust me. You don't need to measure it.
>
>
I can easily hear it
and my hearing does not go near 16K

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

pooua@aol.com wrote:
>>The high pitched sound is usually from the yoke and flyback
>
> transformer
>
>>(actually an inductor) feeding the television's CRT. For most
>
> televisions in the
>
>>United States that frequency is right at 15,734 Hz because the
>
> vertical scan
>
>>rate for NTSC is 29.97 times per second and it draws 525 lines. 29.97
>
> X 525 =
>
>>15734.25 horzontal scanning frequency.
>
>
> That sounds likely, but I have a few questions about that.
>
> 1) Is this same sub-unit on a standard television camera?
> 2) What exactly is converting the electrical energy into sound?
> 3) If this sound is so square in the middle of normal human hearing (16
> kHz is well-within the range of normal human hearing), why have I met
> so few people who can hear it?

Most people can hear it, at least until they are 25 or so
but most people do not know how to focus their listening and blank it out
kind of like what my son does when I ask him if he did his homework
>
> Question 3 is perplexing, because my sister and I were always the only
> people in our classroom or in someone's home who could hear the
> television.
>
> One time, when my sister was hospitalized, her nurse tried to turn on
> the television set for her, but the set did not appear to turn on. The
> nurse was about to leave the room for help with the TV, when my sister
> told him that the TV had just turned on. The screen was still black, so
> he did not know what to think. Then, the TV slowly produced a picture.
> My sister could tell the set was on because she could hear it. No one
> else in the room at the time could hear it.

There is nothing special about hearing this
my hearing is down 30 dB at 8 K(as high as the test at AES went) when
compared to 3K
and I can easily hear it
george
>
> I have worked in a computer call center for several years. At one time,
> we had CRT monitors in the room with us. I was the only person who
> could hear them. I liked to turn the CRTs off when not in use, because
> they hurt my ears. One time, I walked up to two of my associates and
> asked them if they would mind if I turned off the CRTs. One of them
> already knew I could hear the CRTs, but the other one did not. The one
> who did not know was surprised. Naturally, he reached up and turned off
> the set, and asked if I could hear the difference. Then, he turned it
> on. Then, off. Then, on. The other associate, who understood what I was
> experiencing, began to laugh, and called the guy a sadist.
>
>
>>I hear it loudly enough that I can tell when someone walks around in
>
> an
>
>>adjacent room with a television set on.
>
>
> Yes, that is what this is like. When I walk down the sidewalk, I can
> hear the television inside the homes I pass. I can tell if someone
> comes between the television and me, even if they are inside a closed
> room.
>
> I was at a hospital recently. As I walked across the lobby, I heard a
> television. I looked around. Then, I noticed a television camera inside
> a security enclosure box, mostly hidden in the ceiling. It took me a
> little longer to find it than it used to, because I had to locate it
> with just one ear (as I said, I am mostly deaf in the other ear, now).
>

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

On Sat, 12 Feb 2005 00:46:18 GMT, George Gleason
<g.p.gleason@worldnet.att.net> wrote:

>
>There is nothing special about hearing this
>my hearing is down 30 dB at 8 K(as high as the test at AES went) when
>compared to 3K
>and I can easily hear it
>george

Couldn't your hearing be down in the 8k range and still decent in
higher frequencies? It's been quite awhile since I was tested but I
remember that I had a dip in the high-midrange area (right where the
loud guitars and cymbals are!) and then above that I was fine.

Al

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

the sound is caused by the magnetostriction of the power transfomer
16khz is not in the middle of the human range; voice is and it is around 3
khz


<pooua@aol.com> wrote in message
news:1108168896.929130.108230@f14g2000cwb.googlegroups.com...
>> The high pitched sound is usually from the yoke and flyback
> transformer
>> (actually an inductor) feeding the television's CRT. For most
> televisions in the
>> United States that frequency is right at 15,734 Hz because the
> vertical scan
>> rate for NTSC is 29.97 times per second and it draws 525 lines. 29.97
> X 525 =
>> 15734.25 horzontal scanning frequency.
>
> That sounds likely, but I have a few questions about that.
>
> 1) Is this same sub-unit on a standard television camera?
> 2) What exactly is converting the electrical energy into sound?
> 3) If this sound is so square in the middle of normal human hearing (16
> kHz is well-within the range of normal human hearing), why have I met
> so few people who can hear it?
>
> Question 3 is perplexing, because my sister and I were always the only
> people in our classroom or in someone's home who could hear the
> television.
>
> One time, when my sister was hospitalized, her nurse tried to turn on
> the television set for her, but the set did not appear to turn on. The
> nurse was about to leave the room for help with the TV, when my sister
> told him that the TV had just turned on. The screen was still black, so
> he did not know what to think. Then, the TV slowly produced a picture.
> My sister could tell the set was on because she could hear it. No one
> else in the room at the time could hear it.
>
> I have worked in a computer call center for several years. At one time,
> we had CRT monitors in the room with us. I was the only person who
> could hear them. I liked to turn the CRTs off when not in use, because
> they hurt my ears. One time, I walked up to two of my associates and
> asked them if they would mind if I turned off the CRTs. One of them
> already knew I could hear the CRTs, but the other one did not. The one
> who did not know was surprised. Naturally, he reached up and turned off
> the set, and asked if I could hear the difference. Then, he turned it
> on. Then, off. Then, on. The other associate, who understood what I was
> experiencing, began to laugh, and called the guy a sadist.
>
>> I hear it loudly enough that I can tell when someone walks around in
> an
>> adjacent room with a television set on.
>
> Yes, that is what this is like. When I walk down the sidewalk, I can
> hear the television inside the homes I pass. I can tell if someone
> comes between the television and me, even if they are inside a closed
> room.
>
> I was at a hospital recently. As I walked across the lobby, I heard a
> television. I looked around. Then, I noticed a television camera inside
> a security enclosure box, mostly hidden in the ceiling. It took me a
> little longer to find it than it used to, because I had to locate it
> with just one ear (as I said, I am mostly deaf in the other ear, now).
>

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

This is Spehro Pefhany for forever:
> On 11 Feb 2005 15:40:20 -0800, the renowned pooua@aol.com wrote:
>
> >Some people can hear an extremely high-pitched sound generated by
> >television CRTs and television cameras. I have long wondered what
> >frequency this sound is.
>
> No need to measure it. In the US & Canada (and other NTSC countries
> such as Taiwan) the high-pitched sound that you can hear is either
> 15.75kHz (rare these days) or 15.734264kHz. That's when the TV is
> locked to a broadcast. If it's on an empty channel, the frequency will
> be a bit different.

Do you know what are those frequencies for PAL-M?

Sometimes I notice this high-pitched sound coming from my TV... (the 2
TV's I have at home: a 14" Toshiba and a 20" LG, so it's not a fault on
the TV)

[]s
--
Chaos Master®, posting from Canoas, Rio Grande do Sul, Brazil - 29.55° S
/ 51.11° W / GMT-2h / 15m .

"People told me I can't dress like a fairy.
I say, I'm in a rock band and I can do what the hell I want!"
-- Amy Lee

(My e-mail address isn't read. Please reply to the group!)

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

pooua@aol.com wrote:
>>my hearing is down 30 dB at 8 K(as high as the test at AES went)
>>when compared to 3K and I can easily hear it
>
>
> Did AES test your nerve conduction? I have a suspicion that the sound I
> hear is not coming through my eardrums. I am beginning to suspect that
> I hear it through my skull, which means nerve conduction.
>
> Your eardrum may not be able to hear so well, but maybe your ear nerves
> are still able to pick up sounds normally?
>

I have no idea
they gave us headphones and had us press a button when we heard sound
this was end oct 04
but I also feel(subjectivly ) that I can hear things the tests say I
should not be able to
Because I can focus my listening and isolate sounds , like a single
flute out of a flute section from 150 feet away from the orchestra
george

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

pooua@aol.com wrote:
>>It's the horizontal scanning frequency, 15,734.25 Hz for American
>>color TV. Trust me. You don't need to measure it.
>
>
> I need to measure it, to be certain that is what I am hearing.
>
>
>>If humans can hear it, it can't possibly be at 40kHz, because
>>the best human hearing extends to only a bit above 20kHz.
>
>
It could easily be measured with Macfoh (www.macfoh.com) and DPA
measurement mics
george

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

On 11 Feb 2005 16:41:36 -0800, pooua@aol.com wrote:

>>I have worked in a computer call center for several years. At one time,
>we had CRT monitors in the room with us. I was the only person who
>could hear them. I liked to turn the CRTs off when not in use, because
>they hurt my ears.

I can't tell where you are from your headers, but, as others have
said, in North America tv's sweep at 15.75-ish KHz. I'm a geezer
but can still hear a really loud deflection yoke.

CRT computer monitors start at twice that and go up from there,
31.5 KHz and up. Cats and dogs can easily hear an octave or so
higher than *that*, so why couldn't an exceptional human?

Chris Hornbeck

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Chris Hornbeck <chrishornbeckremovethis@att.net> wrote:
>On 11 Feb 2005 16:41:36 -0800, pooua@aol.com wrote:
>
>>>I have worked in a computer call center for several years. At one time,
>>we had CRT monitors in the room with us. I was the only person who
>>could hear them. I liked to turn the CRTs off when not in use, because
>>they hurt my ears.
>
>I can't tell where you are from your headers, but, as others have
>said, in North America tv's sweep at 15.75-ish KHz. I'm a geezer
>but can still hear a really loud deflection yoke.

Until fairly recently (IBM EGA, probably late 1980s), pretty much all the
computer monitors out there in the US ran at NTSC rates and most of them
were video displays in disguise.

>CRT computer monitors start at twice that and go up from there,
>31.5 KHz and up. Cats and dogs can easily hear an octave or so
>higher than *that*, so why couldn't an exceptional human?

Today, computer monitors run at much higher rates than they used to, and
thankfully the sweep whines are now inaudible. Sadly this was not the
case with the Televideo 910 or the (really loud) ADDS Regent.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

On Fri, 11 Feb 2005 17:16:19 -0800, Glenn Gundlach wrote:

>
> pooua@aol.com wrote:
>> > The high pitched sound is usually from the yoke and flyback
>> transformer
>> > (actually an inductor) feeding the television's CRT. For most
>> televisions in the
>> > United States that frequency is right at 15,734 Hz because the
>> vertical scan
>> > rate for NTSC is 29.97 times per second and it draws 525 lines.
> 29.97
>> X 525 =
>> > 15734.25 horzontal scanning frequency.
>>
>> That sounds likely, but I have a few questions about that.
>>
>> 1) Is this same sub-unit on a standard television camera?
>> 2) What exactly is converting the electrical energy into sound?
>> 3) If this sound is so square in the middle of normal human hearing
> (16
>> kHz is well-within the range of normal human hearing), why have I met
>> so few people who can hear it?
>>
> 16 kHz is not square in the middle. When you become an 'old fart' you
> will find that out. 16K is your top octave which you will lose as you
> age. Sorry, I don't like it either but I actually don't miss hearing
> the Horizontal. Been working in commmercial TV for 28 years and haven't
> heard the H in more than 10.
> GG

OK, let's all be honest. How many of you have heard a high-pitched "sound"
very much like 15 KHz yoke, even though there is no yoke? This is
sometimes called "ringing in the ears", and is what I was thinking of when
I asked those questions about tinnitus.

I'm pretty sure I haven't heard 15 KHz horizontal in quite some time, but
right this very moment, I'm hearing the high pitched "eeee" which is
probably attributable to Black Velvet and bud. ;-)

Or maybe three monitors, but they're going at like 70 KHz. I _hope_ I
can't hear that! Could I be hearing magnetorestrictive copuling from four
feet?

Thanks!
Rich

Hah! Magnetorestrictive! That's good enough to leave in! %-}

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

On Fri, 11 Feb 2005 17:02:52 -0800, pooua wrote:

> My objectives are to find out what frequencies I can hear, and to match
> one of the calibrated frequencies from the signal generator against the
> sound I hear from televisions, so that I can finally know what that
> frequency from the television is.

The frequency from the television is approximately 15 KHz.

Don't worry about it.

A, there's nothing you can do about it anyway.
Two, so you can hear TVs. So what?

If you're worried about going deaf in the other ear, go to the otitist,
which you seem to have claimed you've already done.

If you're looking for something to _block out_ the 15 KHz, that's a whole
nother discussion. If this is it, I have some other ideas, but you have to
ask, and then I'll post them under one of my wacko personas. ;-)

Good Luck!
Rich

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

On Fri, 11 Feb 2005 16:52:14 -0800, pooua wrote:

>> It's the horizontal scanning frequency, 15,734.25 Hz for American
>> color TV. Trust me. You don't need to measure it.
>
> I need to measure it, to be certain that is what I am hearing.

Try just listening to it one time. In another post, you mentioned having
to focus on a particular conversation or a particular flute. Do this to
the sound, and ask what it's trying to tell you. It could be an attempt
to communicate from a higher dimension.

Good Luck!
Rich

for further information, please visit http/www.godchannel.com

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

>CRT computer monitors start at twice that and go up from there,
>31.5 KHz and up.

Sent this before engaging the thought process. Computer monitors
have high frequency power supplies that make noise too. Maybe
that was the issue. Tv's do this at sweep frequency for economy;
computer monitors don't, for the same reason.

Chris Hornbeck

 

[Guest]

Archived from groups: rec.audio.pro,sci.electronics.design,sci.med (More info?)

play_on wrote:
> On Sat, 12 Feb 2005 00:46:18 GMT, George Gleason
> <g.p.gleason@worldnet.att.net> wrote:
>
>
>>There is nothing special about hearing this
>>my hearing is down 30 dB at 8 K(as high as the test at AES went) when
>>compared to 3K
>>and I can easily hear it
>>george
>
>
> Couldn't your hearing be down in the 8k range and still decent in
> higher frequencies? It's been quite awhile since I was tested but I
> remember that I had a dip in the high-midrange area (right where the
> loud guitars and cymbals are!) and then above that I was fine.
>
> Al

8k was as high as the test measured so I am not aware of my measured
abilities above that
George