# 5D Mark III sensor cleaning noise (squeaks)



## ddashti (Oct 26, 2012)

When powering on one 5D Mark III, during sensor cleaning, a very noticeable squeaky noise (3-4 squeaks) is produced. It can be heard from around 0.5m away (~1.6 feet).
When turning it off, on the other hand, you can't really hear it (only an occasional squeak).
This has only happened recently.

How bad is this (if bad at all)? And does this need attention?


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## Mt Spokane Photography (Oct 26, 2012)

The cleaning system uses ultrasonics. Some people may have good hearing in the ultrasonic range that could be what is happening.


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## Waterdonkey (Oct 26, 2012)

I hear mine. Three small quiet almost more of a chirp like from a baby chick thats lost its voice... _Ceep, ceep, ceep_.


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## kbmelb (Oct 26, 2012)

I can hear mine. I think of it like using Head and Shoulders shampoo and feeling the tingling. I know it's working.


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## dlleno (Oct 26, 2012)

I doubt that the fundamental or primary ultrasonics are audible to any human, -- unless the distribution of cleaning frequencies is really that broad and some statistically small number of bodies do produce audibles (doubtful). what seems more likely is some subharmonic resonance or other secondary artifact. wouldn't hurt to ask Canon about it but I suspect its no issue. If you're really feeling anal you could experiment to see if what you are hearing is a mechanical artifact -- for example you could take out the memory card(s) just to see if that has any effect and you could plug stuff into the various electrical connectors while running the cleaning routine to see if this has any noise damping effect.


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## Ryan708 (Oct 26, 2012)

my 60d has always done that, it makes a high-low sound 2x.


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## rpt (Oct 26, 2012)

There you go! A whole lot of vampires on this thread!


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## Ryan708 (Oct 26, 2012)

i can also tell if a CRT monitor or TV is on in a room before seeing it even with the volume off, and the ultrasonic cleaners in jewelry stores drive me nuts. Good thing everything is flat-screen now, no high frequencies I can hear with those!


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## thebowtie (Oct 26, 2012)

I wonder how you folks go when you stand near people operating hair dryers or power tools - the high-frequency harmonics must drive you nuts!


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## dlleno (Oct 26, 2012)

just to get anal about this...I'm not aware of any convincing evidence that any human can hear into the ultrasonic region, which of course is why they call it ultrasonic. Not many of us, save perhaps young girls, can hear above 18K, and the world above 20K is just not audible to anyone of normal orgins  . Males above 20-ish and above rarely hear above 18K.

Frequencies in near ultra-sonic region are not usually identified as having a pitch either -- energy in this range contributes to tonal character and timre via harmonics but typically not pitch. Thus the report of an audible chirp that changes pitch is clear evidence to me that this not at all ultrasonic energy detected by extraordinarily gifted hearing ability --it is sonic energy in the ordinary audible range. 

Baring some spurious mechanical resonance within the camera itself there are only two possibilities:

1. intermodulation distortion -- the combination of two or more frequencies above 20K, producing sum and difference frequencies, can result in sonic artifacts that can be heard (Otherwise, audiophiles and would not care about filtering energy above 20K). For example, if the mechanical nuances of the sensor and the ultrasonic mechanism that drives it were to produce two tones at 40K and 25K (both inaudible), then the combination would produce an artifact at 15K which would be audible. I suspect the spectral components of the actual sensor cleaning energy is quite broad (not just one frequency), not to mention dynamic, so this is entirely possible.

2. The Canon system produces energy directly in the audible region. I find this unlikely


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## PeterJ (Oct 26, 2012)

ddashti said:


> When powering on one 5D Mark III, during sensor cleaning, a very noticeable squeaky noise


It's a good feature, how else would your sensor end up squeaky clean?


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## insanitybeard (Oct 26, 2012)

My 7D has always made the squeak on startup and shutdown, which I have always assumed was the normal operation of the sensor cleaning system!


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## sanj (Oct 26, 2012)

PeterJ said:


> ddashti said:
> 
> 
> > When powering on one 5D Mark III, during sensor cleaning, a very noticeable squeaky noise
> ...


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## ddashti (Oct 28, 2012)

I appreciate everyone's help with the issue, as I can now use the Mark III without worrying about startup.
And although it was more than what I was asking for, thanks to _dlleno_ for the in-depth information about ultrasonics. 8)


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## TAF (Oct 28, 2012)

I just took some measurements, and my 5D3 sensor cleaning 'sound' is a series of two smooth frequency sweeps from 100 kHz up to about 125 kHz and back down.

So I would conclude you are hearing some structure in the camera vibrating, and not the actual signal.

The USM frequency is 30 kHz (and it is loud enough for the 2nd and 3rd harmonics to show up quite clearly), which is unfortunately right in the middle of house cats (and dogs) hearing range. Which explains why it can be difficult to get good candid shots of our little furry friends sleeping; the lens focusing is very loud and distinct (to them). This is why I am liking my short 40 so much, as it has no ultrasonic emissions.

I wonder if some of the better shots of lions we see in Canon's literature exist because the lion looked up at the sound of the camera lens focusing?

As an aside, although very few people can hear much beyond 20 kHz in free space, almost everyone can hear to ~40 kHz if the sound is directly coupled to their head ie: via bone conduction. Dukane makes acoustic devices used to find the 'black boxes' from crashed aircraft underwater that ping at 37 kHz, and if one is held behind the ear, I've never met anyone who couldn't hear it loud and painfully clearly. And it isn't just the pop of the pulse, you 'hear' the tone.


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## PeterJ (Oct 28, 2012)

TAF said:


> As an aside, although very few people can hear much beyond 20 kHz in free space, almost everyone can hear to ~40 kHz if the sound is directly coupled to their head ie: via bone conduction. Dukane makes acoustic devices used to find the 'black boxes' from crashed aircraft underwater that ping at 37 kHz, and if one is held behind the ear, I've never met anyone who couldn't hear it loud and painfully clearly. And it isn't just the pop of the pulse, you 'hear' the tone.


Not saying you are wrong but are you sure the frequency heard is 37KHz? Just thinking if it's an electronic device it could easily say halve the frequency to make the 'ping' or just detect it and change to an arbtrary frequency that varied in amplitude depending on received amplitude. 

I'd also imagine you could get the same effect coupling something that resonated at 37KHz to something else that resonated at a lower frequency without using any electronics.


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## AdamJ (Oct 28, 2012)

I'm now a bit worried that I've never heard or felt anything from my 7D during sensor cleaning. :-\


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## kidcharles (Oct 28, 2012)

kbmelb said:


> I can hear mine. I think of it like using Head and Shoulders shampoo and feeling the tingling. I know it's working.



Haha, great analogy. I always loved those commercials, seemed like wonderful nonsense to me. I guess if you poured acid on your head you would also "feel it working" so I'm not sure sensations on your scalp are somehow inherently a good thing.


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## dlleno (Oct 31, 2012)

TAF said:


> I just took some measurements, and my 5D3 sensor cleaning 'sound' is a series of two smooth frequency sweeps from 100 kHz up to about 125 kHz and back down.
> 
> So I would conclude you are hearing some structure in the camera vibrating, and not the actual signal.



indeed, given this data, it is probably sympathetic resonance. so the sweeps themselves -- is this a single tone sweep or what is the bandwidth of the signal that sweeps through 100KHz to 125KHz? I take it you were measuring with a wide band audio spectrum analyzer, measuring actual acoustic energy? 

the "vibrating structure" theory aligns well with the 'shifting chirp' experience as well -- the structure exhibits a natural harmonic resonance at two distinct frequencies as the source sweeps through its range. 



> As an aside, although very few people can hear much beyond 20 kHz in free space, almost everyone can hear to ~40 kHz if the sound is directly coupled to their head ie: via bone conduction. Dukane makes acoustic devices used to find the 'black boxes' from crashed aircraft underwater that ping at 37 kHz, and if one is held behind the ear, I've never met anyone who couldn't hear it loud and painfully clearly. And it isn't just the pop of the pulse, you 'hear' the tone.



fascinating. If he sound energy demonstrably above 20KHz is experienced and detected by a human subject of natural abilities and origins, then it is either a sub harmonic, or it is not detected by the auditory nerve via exitation of the eardrum, which is of course the basis of the "20Hz - 20 KHz" range of human hearing. Conduction via bone structures is an entirely different mode of detection, which could include sub-harmonic exitation of those bone structures or even the eardrum itself, which in this case would easily fall within the auditory range anyway. Also -- sub or supersonic energy can easily be detected, or "felt" even when it is not heard tonally, especially if one's skull is subjected to such a direct mechanical assult 

Incidently -- on the other end of the sonic spectrum, the lowest fundamental frequency of the largest pipe organ is 8 Hz, which is present on only a few organs in the world. Such a pipe is there not because anyone can hear it, but because they can feel it. 

now then, everyone go out and hold your 5D3 up to your skull during the cleaning routine and tell us what you hear!


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## Mt Spokane Photography (Oct 31, 2012)

People can generally not hear ultrasonic tones, but they can dectect pulse trains at much higher than ultrasonic frequencies. They sound like a chirp.

http://grouper.ieee.org/groups/scc28/sc4/Human%20Perception%20FINAL.pdf


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## PeterJ (Oct 31, 2012)

Mt Spokane Photography said:


> People can generally not hear ultrasonic tones, but they can dectect pulse trains at much higher than ultrasonic frequencies. They sound like a chirp.
> 
> http://grouper.ieee.org/groups/scc28/sc4/Human%20Perception%20FINAL.pdf


Hey that was an interesting read ;D. Makes a lot of sense and also made me wonder if some resonant effects also occur in the body, it reminded me of this Russian spying device called "The Thing":

http://en.wikipedia.org/wiki/Thing_%28listening_device%29


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## Pyrenees (Oct 31, 2012)

thebowtie said:


> I wonder how you folks go when you stand near people operating hair dryers or power tools - *the high-frequency harmonics must drive you nuts!*



This is the kind of statement that, if made at high school, would lead to a serious beating. At least, at the high school that I attended


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## cptobvious (Oct 31, 2012)

I've owned three 60D bodies and one of them had the sensor cleaning squeak and the other two didn't. I don't think it's a matter of sensitivity to high frequency noise (the suggestion comes up every time this topic comes up) as my hearing range is tested in the normal range. I think it's manufacturing variances.


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## EYEONE (Oct 31, 2012)

I've been able to hear my XSi, 7D and my 5D Mark III. My wife can hear them too but it seems some people can't. It actually caused some concern when I first got the XSi years ago. I thought it was broken and the internet had very different opinions on it. The people that couldn't here it said it was broken, and others said it was fine. It was pretty funny actually.


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## samthefish (Oct 31, 2012)

It's the mouse that does the cleaning complaining.


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## rpt (Oct 31, 2012)

samthefish said:


> It's the mouse that does the cleaning complaining.


Hey! Not fair! My camera is missing the mouse! I wonder if I can return it?


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## dlleno (Oct 31, 2012)

Mt Spokane Photography said:


> People can generally not hear ultrasonic tones, but they can dectect pulse trains at much higher than ultrasonic frequencies. They sound like a chirp.
> 
> http://grouper.ieee.org/groups/scc28/sc4/Human%20Perception%20FINAL.pdf



This is a fascinating study, but it is not about detecting ultrasonic tones and doesn't really apply to the subject of ultrasonic hearing. The study is about human sensitivity to and detection of pulsed _radio frequency energy_, an energy which consists of oscillating electric and magnetic fields that travel in free (empty) space without air. This is the energy that, for example lives in the Amateur radio bands, well above the FM broadcast band for example, and well into the microwave region. This is the type of energy that eminates from Television brodcast antennas, cell phone towers, cordless phones, your laptop's WiFi system, and microwave repeaters. The study is not about ultrasonic "tones" and it is not about acoustic energy.

Acoustic energy (sound) consists of _mechanical pressure waves _ and cannot be transmitted without a medium (such as air or water). This type of mechanical energy requires an energy source of mechanical origin -- something, like a speaker cone, clapping hands, or Placido Domingo's vocal chords, has to move the air. The energy used to clean the sensor is acoustic in nature -- this energy is vibrating the bejeebers out of somethign (the sensor) to shake dust loose. In this sense, we can think of the sensor as a really high frequency tweeter that no one can hear. In any case, if the acoustic energy emitted by the camera is within the set of frequencies to which your ears are sensitive, you will hear something but it won't be the 100Khz cleaning frequency itself. The question is -- how can a sensor cleaning device operating at six times the upper threshhold of human hearing result in an audible sound? 

by far the best insight into what actually happens in sensor cleaning has been provided by *TAF * . Very nice info sir! *TAF * showed that the fundamental acoustic energy of the cleaning routine sweeps from 100KHz to 125HKz and back. there is no way that any human being of natural orgins and abilities can hear this. The acoustic pressure waves reaching the ear just do not produce any response from the eardrum. no way. 

of course, if you blast your head with a tremendous high-energy assult of air pressure waves at 100KHz, something is bound to happen internally (to your body) that can be detected. but this is not what is happening with the tiny little speaker we know as the sensor cleaning routine. its a tiny little tweeter producing a very small amount of acoustic energy at frequencies that no one can hear. 

what is far more likely, as *TAF * has rightly pointed out, is that there is some sympathetic or natural mechanical resonance that occurs within the camera structure itself -- much like the vibrations you hear from your dashboard when driving on certain roads... The structures themselves are responding at some subharmonic (a sub multiple of the 100KHz fundamental) that is within the range of human hearing. Note that if this sub-harmonic were present naturally in the sensor cleaning function itself you would hear a high-pitched tone that would sweep up and then back down, perhaps at the 7th or even 8th subharmonic (something between 12Khz and 18 KHz) The fact that no one has reported hearing a smooth frequency sweep is clear evidence to me that TAF is right -- there are fixed frequency mechanical resonances in the camera that will respond, some more than others, when the cleaning "sweep" reaches the right point in its sweep. Note that if there are two or more natural structural resonances within the camera, then you will hear two or more distinct tones or perhaps they will sound like chirps. in any case, you are not hearing the sensor cleaning function, you are hearing an artifact or side-effect of it. 

what is clear to me , based on the above, is that (1) there is a very wide variation from camera to camera structural resonances, and owner to owner hearing abilities, with respect to what is actually heard during the cleaning routine, and (2) human hearing cannot possibly be used to measure the presence of or effectiveness of the cleaning routine because the cleaning routine itself cannot be heard!. If you hear something, then your ears are sensitive to whatever frequencies your camera's internal structures are vibrating at. Thats about it  . Moreover, when you compare your audible results with someone else, then you are not comparing your respective cleaning systems, you are comparing your own hearing sensitivies and the natural structural resonances present in your respective camera bodies


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## Mt Spokane Photography (Oct 31, 2012)

dlleno said:


> Mt Spokane Photography said:
> 
> 
> > People can generally not hear ultrasonic tones, but they can dectect pulse trains at much higher than ultrasonic frequencies. They sound like a chirp.
> ...


No argument here, I was just pointing out that there is still lots of things that we do not understand about hearing. We do not even understand how bone conduction allows some people to hear ultrasonics, just conflicting theories that may or may not be correct. I tend to believe the theory about bypassing the eardrum and directly stimulating the cochlea makes sense, since many animals actively hear and use ultrasonic sounds. Others believe that directly stimulating the brain is making it happen, and of course, it could be harmonics being generated in the bone structure that vary from person to person.
Its almost certainly the pizzoelectric ultrasonic driver that excites the sensor generates many harmonics that some can hear.


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## dlleno (Oct 31, 2012)

definately lots we don't know about the abiity of humans to perceive or detect external stimulii of various sorts (especially at high energy levels) in ways that are perceived to be 'hearing'. thats for sure -- total agreement there. For example, the ability to detect the application of mechanical energy directly to parts of the body (like vibrating the skull at ultrasonic frequencies) is amusing, too. Imagine the variance among individuals, i.e. size of the head, bone density, etc, etc. and maybe those with 5D3s can try pressing their cameras bodies against their heads!

The physiology and mechanics of detecing low levels of true acoustic energy transmitted via air ("hearing") is relatively well understood though, and more closely applies to the phenomena of hearing the sensor being cleaned. 


this has been a cool thread, actually, an amusing departure from Dxo scores arguments


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## Mt Spokane Photography (Oct 31, 2012)

dlleno said:


> definately lots we don't know about the abiity of humans to perceive or detect external stimulii of various sorts (especially at high energy levels) in ways that are perceived to be 'hearing'. thats for sure -- total agreement there. For example, the ability to detect the application of mechanical energy directly to parts of the body (like vibrating the skull at ultrasonic frequencies) is amusing, too. Imagine the variance among individuals, i.e. size of the head, bone density, etc, etc. and maybe those with 5D3s can try pressing their cameras bodies against their heads!
> 
> The physiology and mechanics of detecing low levels of true acoustic energy transmitted via air ("hearing") is relatively well understood though, and more closely applies to the phenomena of hearing the sensor being cleaned.
> 
> ...


I'd love to be able to once again to hear even 4K hertz with a hearing aid! My hearing has gone south to the point where a implant is likely to happen. I've tried all of the hearing aids, including one that shifts high frequency sounds into my hearing range. It actually works pretty well at allowing me to hear sounds that I could not otherwise hear, even if the pitch is totally wrong.
Its very frustrating to not be able to understand what people are saying, even with the best hearing aids. 
I've looked into the various technologies for implants, bone conduction systems, direct mechanical stimulation of the ear drum, and discussed them with my doctor, who has done a lot of the original research involving many of the alternate methods, they all have drawbacks, and he is happy to discuss pros and cons. So far, only the implants seem to be pretty much the gold standard, but I keep watching for a breakthru. 
At this point, I do not want to give up what hearing I have, I only have one ear that has any hearing at all, but the time is coming soon when I will be better off with a implant.


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## tron (Oct 31, 2012)

AdamJ said:


> I'm now a bit worried that I've never heard or felt anything from my 7D during sensor cleaning. :-\


Maybe because it doesn't work? ;D
Seriously now I haven't noticed anything on my 5DMkII and 5DMkIII. They must be broken too... ;D


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## dlleno (Oct 31, 2012)

Dude Mt. Spokane thats no good. I've got industrial noise and age related losses that frustrate my wife, but nothing like you or rush limbaugh. these outside-the-box methods are awesome and still emerging, to be sure ,and I certainly hope you are able to find some relief or improvement! 

@ Tron/AdamJ lol forgive my reversion back to the technical -- I'd say that if you can't hear it, and you're hearing is ok/normal for your age, , then that is good! Best case is that a teen-aged girl can't hear the sensor cleaning routine  then you know that no parasitic resonances are happening in the camera!


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## TAF (Nov 1, 2012)

dlleno said:


> TAF said:
> 
> 
> > I just took some measurements, and my 5D3 sensor cleaning 'sound' is a series of two smooth frequency sweeps from 100 kHz up to about 125 kHz and back down.
> ...



Yes, actual acoustic energy.

I am using a device specifically intended for detecting ultrasonic emissions, the Wildlife Acoustics EM-3:

http://www.wildlifeacoustics.com/products/ultrasonic-monitoring/em3

I'm still learning to use the instrument, so I cannot yet ascertain the purity of the sweeping tone. It is fairly narrow on the spectrum display (which is very small), but until I can expand the range (or more correctly reduce the bandwidth so as to enlarge the displayed signal), I can't answer that.

I will post more when I get there.


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## TAF (Nov 1, 2012)

Mt Spokane Photography said:


> People can generally not hear ultrasonic tones, but they can dectect pulse trains at much higher than ultrasonic frequencies. They sound like a chirp.



In the case of the Dukane pinger, you don't even need to hold it against the bone behind your ear to hear the once per second tick; it sound like a fairly loud clock. Nothing special to that, the square wave pulse is obvious, and I suspect it is the end diaphragm of the device popping.

What I find interesting is that once you do put it against the bone behind your ear, and if you listen really carefully in a quiet room, you will start hearing the actual tone that comprises the pulse. Imagine the highest pitch squeak you can, and then picture it getting higher in pitch still. That's what it sound like. It is a very odd experience.

This doesn't really surprise me, though. The human ear is a very efficient acoustic filter, optimized for the frequencies we're supposed to hear. It does a pretty decent job of reducing the 'out of band' signals that we're not really intending to listen for (the text book "Fundamentals of Acoustics" covers the math pretty well; my copy is at the office so I'll post the authors name tomorrow night). But when you bypass the filter and put the input directly into the detector, finding that the little cilia in there vibrate at a much higher frequency than expected isn't shocking to me. 

I have a few transducers that will operate out well past 50 kHz. I'll have to try a few sine waves (no impulse to confuse things) and see what I can hear. My cats may not like the experiment (the always sit outside the door to the workshop and meow when I play with ultrasonics), but I think I can confuse them for a few minutes for science.


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## dlleno (Nov 1, 2012)

lol nice work TAF I hope your cats survive the experiment  indeed, bypassing the natural low pass filter of the ear is comparitively uncharted waters. Here's hoping something useful appears in time for Mt. Spokane!


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## TAF (Nov 3, 2012)

Follow-up:

1. The text book authors are Kinsler and Frey (and two other guys who I have forgotten)

2. My experimental results. Putting the transducer to the bone behind my ear and exciting it with a sine wave, I could hear a tone up to around 50 kHz. I did have to keep increasing the drive level. I won't be repeating that experiment; above 50 kHz or so, all I got was a headache. As for my four cats; the young ones (3 and 4) sat by the door staring curiously, the middle aged one (12) meowed, and the older one (15) slept (I think she's deaf).

3. All this got me to thinking, so I did a literature search. A report from the Journal of the Acoustical Society of America (Corso J. Bone-conduction thresholds for sonic and ultrasonic frequencies. J Acoust Soc Am 35:1738-43, 1963) reports that the traditional human guinea pig (aka college students between 18 and 24 years of age) can hear out to 100 kHz under these conditions.

4. Interestingly enough, the other thing I found was reference to some research where they used an ultrasonic signal which was amplitude modulated, very much like an AM radio (eg: a 100 kHz carrier and a 2 khz voice band signal) and the test subjects heard not the 100 khz signal but the modulation. Very interesting result.

My apologies for the digression. I think you need not concern yourself with a small squeak.

When I learn how best to use the test gear, I'll report back if I find anything interesting about the cleaning sweep.


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## tron (Nov 4, 2012)

TAF said:


> My cats may not like the experiment (the always sit outside the door to the workshop and meow when I play with ultrasonics), but I think I can confuse them for a few minutes for science.


Nooo poor cats. If there is not such thing as ... cat ear plugs ;D put them in a room far away and close the door.


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## HoneyBadger (Nov 4, 2012)

I have had two 5dIII (returned one) both made 2 high pitch noises when turning it on and off while it said it was cleaning so I would not worry about it. I am also one of those can can tell if a crt is on anywhere in the house. And those damn apple chargers for their laptops drive me crazy with their high pitch noise!


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## dlleno (Nov 6, 2012)

HoneyBadger said:


> I have had two 5dIII (returned one) both made 2 high pitch noises when turning it on and off while it said it was cleaning so I would not worry about it. I am also one of those can can tell if a crt is on anywhere in the house. And those damn apple chargers for their laptops drive me crazy with their high pitch noise!



If you are hearing CRTs from NTSC Televisions, you know you can hear 15.7 KHz then :-D Computer monitors generally run well above the threshold of human hearing. For example, a CRT capable of 1024 lines at a 60 Hz refresh rate runs at about 64KHz, which means in order for these devices to be audible you would have to be hearing some subharmonic, which of course is quite possible. 

laptop chargers are a different animal. Unlike the CRTs with flyback transformers, these are switching supplies running well above the audio range, However, it is still not uncomon for these to produce some subharmonic mechanical vibration or even a real resonance in the audio range as a side-effect. It wouldn't suprise me if these produce acoustic energy well below the upper threshhold of human hearing.


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