You talk about filtering, and then talk about an "anti-wave" (opposite wave) that is on the net, that one should avoid. But this is exactly what I'd like to see - as it could be handy round my place where the local school across the road has taken to using these bloody things as their school bell (playtime, lunchtime, etc etc). Drives me nuts. Is this 'anti-wave' thing not the same as Active Noise Reduction - such as pilots headsets etc. If not, can you explain?
@HiTimeNZ well the theory is sound, but it is almost impossible to implement (except may be in the headphones)....the reason is coherence. It is almost impossible to match the sounds so precisely that they cancel out - this problem is even more aggravated by the fact that sound from the source and anti-wave speaker are also bouncing off different surfaces introducing phase differences which again makes matching impossible. @Sixtysymbols correct me if I'm wrong...
however an acura with a gdi engine(gasoline direct Injection) has microphones in the speakers to pick up unwanted engine noise and cancels the "sound wave disturbances".
Well the way some thing sounds (called its timbre) is due to its different harmonics. So regardless of how that instrument is played it will always produce the same harmonics. The instrument itself is just a fancy looking amplifier
But the spectators at world cups doesn't blow such nice tones as the trombonists you have there. How does the frequency spectrum differ from those clear notches when the vuvuzela is played the wrong way, like you did at 0:27?
The worldcup season was pretty upsetting. Such an utter disrespect for the arts. Tryin' to watch a vuvuzela concert, and the people start playing soccer and people start shouting about that :(
This is a technological "solution" to what is really a social problem. Clearly, the "instruments" in question need to be banned, with capital punishment instituted for violators. With a possible exception written in for the Horn of Boromir.
@sbergman27 People should be tared and feathered when using a vuvuzela. They should be excluded from society. It is a felony to make sounds. Expression of the self is a felony and will be punished. Free speech is overrated and is to be abolished. Signed Hitler.
@TheSun19901 You don't have to get rid of ALL of the sound (and indeed, you can't) but that would give you the option to get rid of the appropriate amount so that you can hear the commentator well.
Isn't it possible to put a microphone "outside" which records only the hum and the spectators and just subtract what it hears from the commentators microphone? Wouldn't that be better then zeroing the frequency?
What happens if you take out less/more of the notch depending on how the soundwave is peaking/troughing? It seems like if you correlate the two you would be able to take more vuvzela out when the peak is low and retain quality.
In our defence, I think you'll find that opinion is divided as to whether or not the vuvuzela is an instrument. Try searching YouTube for "vuvuzela orchestra"...
@DickHead69able Thanks for the question. There are a lot of good answers to this in the comments below. They're worth reading for different "takes" on the problem.
Briefly, they supply an arbitrary recording of a vuvuzela which they claim is in "anti-phase" with all other vuvuzela sounds (e.g. during a football match). This is impossible. Phase cancellation necessitates that the *same* waveforms are added together, but with a phase difference. See also @taraz3d's comment below.
@DickHead69able I guess that hypothetically, if you have a sound, divide it into component frequencies and phase shift each component to make it out-of-phase with the original, then playing the out-of-phase recording and original recording SIMULTANEOUSLY would make them cancel out. The problem is that they need to be perfectly synchronized (to within a millisecond, say). Also, I doubt any of this works unless the original vuvuzela recording is identical to the vuvuzela you want to cancel.
For phase cancelation to work its got to be the mirror image signals that you merge in and out of phase , if there is a small differential between the 2 a freq will be herd
You've (probably) got the pitch wrong. Vuvzelas are at least supposed to be in B♭ and not A, so the correct frequency should be about 233 Hz and its harmonics.
@Gameboygenius There's quite a large amount of variation in the pitch of vuvuzelas (certainly within a +/- 10 Hz range). The program used in the video gives the correct pitch for a 440 Hz test signal so it is accurately measuring the fundamental and the harmonics of the vuvuzela we used.
I dont understand why the phase cancelation method wouldnt work....... I thought that's the method that was going to be used to process the sound, not notch filtering........
@elmonorizzo He warns against "anti-sound" MP3's, and that has nothing to do with sound processing on a computer. To cancel a sound, you have emit the same sound, same waveform, amplitude, frequency but with opposed phases : If you move, say 34 cm for a 440 hz sound, relatively to both sources, amplitudes add up. For an sound cancelation device to work, it should generate the anti-sound real-time, like a negative of the incoming sound, very near the ear. You cannot record this.
I've always known phase reversing to be used in the studio all the time to crop out vocals or other instruments in a workable eq band??? maybe not complete cancellation but mostly gone?
@wyvernlord23 I'm not sure, could it be something like it is not enough to create an anti-phase but you would need to syncronize that anti-phase with every vuvuzela that is playing so that every peak and valley would line up and cancel out?
If you can't navigate to this just send me an e-mail (Google "Philip Moriarty Nottingham" for my address).
Note that it's very basic and not particularly elegant code - I threw it together quickly for the video. National Instruments has a somewhat more sophisticated vuvuzela filter VI available from its website.
His filter would only work if all vuvuzelas were tuned more or less together. Real ones vary by about +/- 0.2 semitone, which makes filtering more difficult. Also, notch filtering can't get rid of people who can't play at all and make random noises, and people who are clever and figure out how to play the sub-octave tone.
Thanks for your comments on the video. @metabog raises exactly the point you make in a comment below. My response to metabog below also addresses your comments.
Lol, the anti-phase thing is such a misleading idea, it's impossible to always have the recorded vuvuzela constantly in anti-phase with some arbitrary vuvuzela sound in the background.
I also think it's much harder when there's a huge crowd of vuvuzelas with slightly (or considerably) different pitches (the bee-swarm noise), cause then it practically eats up a huge part of the spectrum, it's not just a few related harmonics.
@metabog It's also smack down in the middle of the human vocal range...
I wish there were more signal processing videos, like the Fourier one, but I know it's somewhat detached from general physics, but it's such an arcane and interesting subject with lots of applications.
@metabog Nice comment! Filtering out a single vuvuzela is indeed signficantly less challenging than trying to filter out a vuvuzela "chorus". The video was just to discuss the concept of filtering for those unfamiliar with the idea.
I can't think of an area of physics that *doesn't* involve Fourier analysis. One astronomer I know has said that it's "what physicists always do when they can’t think of anything better"! [Google "telescoper colour Fourier"].
@Vennificus Nice suggestion! Coincidentally, I've recently been thinking about the Casimir effect for another potential Sixty Symbols video. "Stay tuned", it might appear at some point...
nice video. i'd like to see software that could accurately process recorded music of a band and transcribe the different music parts. that would be nice and save some time learning new songs :) however anything so far i've seen try to do this is pretty bad. i find it interesting how a musician good at listening can separate this out and write out the parts (or even identify the current 'chord' being played fairly easily, but to do it automatically seems very difficult.
Even we can filter out the annoying BZZZ from TV, we can't hear the cheering sounds and "we are the champion" song anymore....... Because no one in the stadium will attempt to do it
The problem is that it works when all the vuvuzelas have the same lenght, but when you filter the harmonics of a wide variety of vuvuzelas the voice keep getting cut and cut.
why do TV stations have to "filter" it out? why can't they just mute the input signals from the source or lower the volume and make the commentary's voice louder?
That implies that the commentator is in a place separate from the ambient vuvuzela noise, ie in a studio in Tokyo, and not right in the middle of the stadium between the fans. Besides, TV stations might also be interested in getting a clear sound of the shoes hitting the ball and the referee's whistle which are impossible to record independently of the ambient noise.
Wouldn't different vuvuzelas and different players have different frequency values for the harmonics, potentially right across the spectrum - making the task of usefully subduing the noise more or less impossible for a large crowd of vuvuzela .. operators? (I think the term 'player' is possibly overdignifying what they do)
@bobbyt2012 It is indeed LabVIEW. LabVIEW is ideal for frequency spectrum analysis and filtering because it combines simplicity and flexibility. (And no, I'm not employed by (nor receiving commission from) National Instruments!).
@Moriarty2112 Excellent to get feedback from you! I have access to LabVIEW, but I have no formal training in using it. I was trying to imitate what you were doing in Audacity with no avail. If you don't mind me asking, which subprogram were you using? Is there video or something that can teach me? Thanks again for all the work you put into this, it is extremely educational.
@bobbyt2012 I can e-mail you the LabVIEW "code" (i.e. virtual instrument (VI)) if you like. If you Google "Philip Moriarty University of Nottingham staff listing" you will find my e-mail address. Send me an e-mail and I'll send you the LabVIEW VI.
The first major task I had when I started as a lecturer in Nottingham in 1997 was to "re-vamp" one of our undergraduate laboratory courses so that it was based on LabVIEW. I hated LabVIEW initially but grew to love it.
I thought the easiest way to filter out the vuvuzela was to hit the b*st*rd who's using it. Unfortunately that means hitting thousands of people but with team work we can do it people, who's with me? Yeeeeeeeeaaaaaaaaah!
@Pazma1 according to a leading Indian news paper, more than 1 mil vuvuzelas were sold in SA alone....... looks like there are a lot more than thousands of people to hit :)
Notch filtering works great, until they start manufacturing vuvuzelas with slightly different lengths. Also, if you start getting them in different frequencies, you'll also start getting beat frequencies off of them, making more notches required. Pretty soon the notches will completely cover the spectrum, and they become a fail as a solution.
From what I've heard is that the anti-phase principle is being used in certain cars to make the motor sound less noisy, I doubt it can completely cancel out that noice. It's supposed to work in the cars and probably do.
Why would it not work for something like a vuvuzela?
@FaintSnow: because you cannot control the frequency tightly - little imperfections and differences in dimensions cause the frequency to wander - and you can't control the phase. A motor is a single source; the vuvuzelas are multiple.
NIce, but a bit late, not merely because about 85% of the World Cup matches are history, but because none of it is news anymore nor is the content ludically educational. Just do a boolean "vuvuzela"+"filter". So, while I've never rated any of Sixty Symbols with thumbs down, this time I will.
@sixtysymbols Here is an article that explains what you did but without the science. gizmodo (dot) com/5563522/simple-software-can-filter-out-that-vuvuzela-whine-from-world-cup-broadcasts
@DanHadan As the person speaking in the video, I'd like to respond to your thoughtful comments. You're absolutely correct, we don't want "unconditional cheerleaders". There are also many web pages which deal with vuvuzela filtering, as you say.
Our aim with this video was, however, to make the discussion as simple as possible so that those who had never heard of a notch filter or a frequency spectrum could get an insight into how the filtering works. Judge us on that criterion!
Thank you for your reply. Please, do note that I started the initial comment with the term "nice" & that certainly encompasses keeping "the discussion as simple as possible so that those who had never heard of a notch filter or a frequency spectrum could get an insight into how the filtering works." My comment concerned timing (late) & lack of ludic aspect; rating and comments not being disabled, I didn't refrain from rating and explaining that rating.
Thank you for your reply. Please, do note that I started the initial comment with the term "nice" & that certainly encompasses keeping "the discussion as simple as possible so that those who had never heard of a notch filter or a frequency spectrum could get an insight into how the filtering works." My comment concerned timing (late) & lack of ludic aspect; rating and comments not being disabled, I didn't refrain from rating and explaining that rating.
How about using the noise sample feature in audacity, maybe that would work better than notch filtering. take a 10 second sample of just the vuvuzela, and apply that filter to the (voice/vuvuzela) combination. I haven't tried it myself however it's worth a shot :)
@culwin Check out MysterGuitarMan's channel; he made a video in which he played loads of vuvuzelas and autotuned the drone into a pice of classical music!
ooh so thats a vuvuzela....thank you dear for that explanation, for myself personally , my only reaction would be to say that i remember there used to be a medication which came in a tube with a nozzle on it that the doctor would prescribe you for the treatment of hemorrhoids, suffice it to explain how the medication and the vuvuzela would be correctly and preferably used....they even look alike save for the difference in dimensional scale,and they are both painful when employed in proper manner
@MattLiViD Even then, they still are recording from the football pitch, so unless you don't want to hear the crowd and the cheers and the soccer players and the referees, there is always going to be that incessant drone.
Small technical complaint: the diagram at 0:40 shows the wrong harmonic structure. The fundamental harmonic shouldn't be node to node, but antinode to antinode. This is due to the fact that it is open at both ends. This gives the same pattern of frequencies, so for the most part it's a distinction without a difference, but still.
@odysseus9672 --- Pressure nodes are displacement antinodes, and vice versa. But you're right - I should have more carefully explained this. The diagram at 0:40 shows pressure nodes at the ends of the tube. If it were drawn for displacement then you're correct, they would be antinodes.
@Alhoshka --- All recording was done with the basic version of Audacity (ver 1.2.6) - no additional plug-ins required. However, the spectral analysis was done with LabVIEW, not Audacity.
Can't you make a new "anti-sound" for every specific occasion? One mic for the reporter and one or several for the immediate surrounding? Or place the reporter in a concrete bunker at a nearby moon?
technically isn't it the first harmonic, then the third, then the fifth harmonic?? its a tube with a closed end......standing waves can only produce 1,2,3,4... harmonic waves.
@LilReaper1010 Thanks for raising this. The harmonic spectrum for trumpets and trumpet-like instruments is more complicated than you might think. Google "hyperphysics brass" for a discussion - I found this web page very enlightening.
The vuvuzela is also conical which in principle means its spectrum should be like that of an open tube. In any case, in the video we see harmonics at 220 Hz, 440 Hz, 660 Hz etc... i.e. fo, 2fo, 3fo (where fo is the fundamental) and not fo, 3fo, 5fo....
@Easwarvasi6 There has to close synchronisation of the original signal and the cancellation signal in order for it to work. This is why noise cancelling head-phones incorporate a microphone - a phase-shifted version of the sound is applied in "real time". There is no way that a recording of the vuvuzela drone from another World Cup game is going to synchronise with that from a different match. There's also the issue of the placement of the "anti noise" source...
@Moriarty2112 The anti-phase is similar to how the double slit experiment will not work with two sources, one would have to use one source (because two different sources would never be in phase)?
@Easwarvasi6 I think it's because for waves to cancel, they have to be positioned exactly on top of each other, which is nearly impossible if you have waves coming from hundreds or thousands of vuvuzelas.
1. the anti-wave will never correctly "align" simple by playing another sound. If it were that easy, just a second Vuvuzela in the stadium would cancel it out.
2. you have not one but many Vuze's. For everyone you would have to play an anti-wave, because their phase is not in sync.
3. although one Vuze may have very distinct frequencies, just a slightly different build will make another frequency. You would need an anti-wave for every possible Vuze (also problem for notch filters)
how should you be able to make such an mp3, wichtout knowing exactly how the vuvuzelas will sound like at a given time and exact location in a stadium IN THE FUTURE? its a bit like the wireless network cables they sell on ebay, where you get literally nothing if you buy them, except that in this case you just get vuvuzela sound.
Not only that, you'd have to know the exact moment when to start playing it, down to the nanosecond, possibly even more accurately in order to even cancel one properly.
@fossil98 Entirely agree - I love Audacity and it was by far the easiest way to capture the samples of the vuvuzela. However, the only thing I don't like about it is that it's not easy to isolate and zoom in on particular regions of a frequency (Fourier) spectrum. That's why LabVIEW is used for the spectral analysis in the video.
amazing last name.
Talis116 1 day ago
He's using Labview! Hell yeah.
elijohua 1 week ago
You talk about filtering, and then talk about an "anti-wave" (opposite wave) that is on the net, that one should avoid. But this is exactly what I'd like to see - as it could be handy round my place where the local school across the road has taken to using these bloody things as their school bell (playtime, lunchtime, etc etc). Drives me nuts. Is this 'anti-wave' thing not the same as Active Noise Reduction - such as pilots headsets etc. If not, can you explain?
Cheers, Duncan.
HiTimeNZ 2 weeks ago 2
@HiTimeNZ well the theory is sound, but it is almost impossible to implement (except may be in the headphones)....the reason is coherence. It is almost impossible to match the sounds so precisely that they cancel out - this problem is even more aggravated by the fact that sound from the source and anti-wave speaker are also bouncing off different surfaces introducing phase differences which again makes matching impossible. @Sixtysymbols correct me if I'm wrong...
amiyaiitkgp 1 day ago
Moriarty rocks.
Diemedes 3 weeks ago
however an acura with a gdi engine(gasoline direct Injection) has microphones in the speakers to pick up unwanted engine noise and cancels the "sound wave disturbances".
SpikeZeek 1 month ago
Well the way some thing sounds (called its timbre) is due to its different harmonics. So regardless of how that instrument is played it will always produce the same harmonics. The instrument itself is just a fancy looking amplifier
CommanderdMtllca 1 month ago
But the spectators at world cups doesn't blow such nice tones as the trombonists you have there. How does the frequency spectrum differ from those clear notches when the vuvuzela is played the wrong way, like you did at 0:27?
KaptenN 2 months ago in playlist sixty seconds
@KaptenN you do the same thing, and use an eq or noise cancellation program to kill it.
the WAVES bundle has an excellent program to do this.
TheRumpletiltskin 1 month ago
@TheRumpletiltskin So even when a vuvuzela is played badly it will still make clear notches on the frequency spectrum?
KaptenN 1 month ago
@KaptenN they wont be clear notches, but they will (for the most part) be noticeable in contrast to a person speaking.
TheRumpletiltskin 1 month ago
The worldcup season was pretty upsetting. Such an utter disrespect for the arts. Tryin' to watch a vuvuzela concert, and the people start playing soccer and people start shouting about that :(
FHomeBrew 2 months ago in playlist sixty seconds
A woman blew her vocal cords out playing one of those things.
Desmaad 2 months ago
Notch filters for the win!
MikeRoePhonicsMusic 4 months ago
This is a technological "solution" to what is really a social problem. Clearly, the "instruments" in question need to be banned, with capital punishment instituted for violators. With a possible exception written in for the Horn of Boromir.
sbergman27 5 months ago
@sbergman27 People should be tared and feathered when using a vuvuzela. They should be excluded from society. It is a felony to make sounds. Expression of the self is a felony and will be punished. Free speech is overrated and is to be abolished. Signed Hitler.
zurechtweiser 4 months ago
@zurechtweiser Get a life.
sbergman27 4 months ago
@sbergman27 That's right he should. But that's not that easy. Elvis tried getting a life, too but he's still dead.
zurechtweiser 4 months ago
tree pound
VastliverpoolCL 5 months ago
@TheSun19901 You don't have to get rid of ALL of the sound (and indeed, you can't) but that would give you the option to get rid of the appropriate amount so that you can hear the commentator well.
jamma246 5 months ago
I love this teacher the most. He's all about practice. I couldn't imagine doing a course entirely built upon theory - I have do DO SOMETHING haha
Speekerful 6 months ago
Trueout!
AduhAwas 7 months ago
I like how he says three
Alexsuppan 7 months ago
Ha Audacity. Love it!
genericmember1 9 months ago
Isn't it possible to put a microphone "outside" which records only the hum and the spectators and just subtract what it hears from the commentators microphone? Wouldn't that be better then zeroing the frequency?
ElMirc 11 months ago 3
Moriarty uses Audacity!
Chaosynthesis 1 year ago 35
What happens if you take out less/more of the notch depending on how the soundwave is peaking/troughing? It seems like if you correlate the two you would be able to take more vuvzela out when the peak is low and retain quality.
rockyraccoon 1 year ago
i love audacity !
ThePaintballer12 1 year ago 2
Is that Fourier transform you use to get the spectrum?
backstabingliar 1 year ago
He makes me think of Dr Gordon Freeman from Half life :D
TheLordZixx 1 year ago 5
Vuvuzela is not a instrument.
Do some research first!
HeitorShew 1 year ago
@HeitorShew
In our defence, I think you'll find that opinion is divided as to whether or not the vuvuzela is an instrument. Try searching YouTube for "vuvuzela orchestra"...
Best wishes,
Philip Moriarty (person speaking in video)
Moriarty2112 1 year ago
@Moriarty2112 Hi Philip
Just wondering, could you explain why the anti-phase stuff is nonsense and how they claim it works please?
Thanks :D
DickHead69able 1 year ago
@DickHead69able Thanks for the question. There are a lot of good answers to this in the comments below. They're worth reading for different "takes" on the problem.
Briefly, they supply an arbitrary recording of a vuvuzela which they claim is in "anti-phase" with all other vuvuzela sounds (e.g. during a football match). This is impossible. Phase cancellation necessitates that the *same* waveforms are added together, but with a phase difference. See also @taraz3d's comment below.
Philip
Moriarty2112 1 year ago
@DickHead69able I guess that hypothetically, if you have a sound, divide it into component frequencies and phase shift each component to make it out-of-phase with the original, then playing the out-of-phase recording and original recording SIMULTANEOUSLY would make them cancel out. The problem is that they need to be perfectly synchronized (to within a millisecond, say). Also, I doubt any of this works unless the original vuvuzela recording is identical to the vuvuzela you want to cancel.
Paulginz 9 months ago
For phase cancelation to work its got to be the mirror image signals that you merge in and out of phase , if there is a small differential between the 2 a freq will be herd
wazroady 1 year ago
why won't the anti-phase work?
Nocturnox65 1 year ago
@Nocturnox65 For it to work it has to be the same signal in and out phase to do this , so its not impossible but really hard to do ,
wazroady 1 year ago
what program do you use for filtering?
barbalote2 1 year ago
You've (probably) got the pitch wrong. Vuvzelas are at least supposed to be in B♭ and not A, so the correct frequency should be about 233 Hz and its harmonics.
Gameboygenius 1 year ago
@Gameboygenius There's quite a large amount of variation in the pitch of vuvuzelas (certainly within a +/- 10 Hz range). The program used in the video gives the correct pitch for a 440 Hz test signal so it is accurately measuring the fundamental and the harmonics of the vuvuzela we used.
Best wishes,
Philip (person speaking in video)
Moriarty2112 1 year ago
I dont understand why the phase cancelation method wouldnt work....... I thought that's the method that was going to be used to process the sound, not notch filtering........
elmonorizzo 1 year ago
@elmonorizzo He warns against "anti-sound" MP3's, and that has nothing to do with sound processing on a computer. To cancel a sound, you have emit the same sound, same waveform, amplitude, frequency but with opposed phases : If you move, say 34 cm for a 440 hz sound, relatively to both sources, amplitudes add up. For an sound cancelation device to work, it should generate the anti-sound real-time, like a negative of the incoming sound, very near the ear. You cannot record this.
taraz3d 1 year ago
"amateur trombonist....self described. <--- I lol'd!
cuntylishus 1 year ago
They use audacity. awesome.
shoffing 1 year ago 6
I've always known phase reversing to be used in the studio all the time to crop out vocals or other instruments in a workable eq band??? maybe not complete cancellation but mostly gone?
Jtoneloc 1 year ago
This is something that audio engineers do everyday.
Jtoneloc 1 year ago 2
everyday i wish everyone who has a vuvuzela will die
counterclockwise123 1 year ago
Awww. I REALLY want to know Why the "less reputable company's" filtering system doen't work.
Does the vuvuzela sound cause superpositioning and make it louder or what?
If any one knows can you please tell me? Its driving me crazy.
wyvernlord23 1 year ago
@wyvernlord23 I'm not sure, could it be something like it is not enough to create an anti-phase but you would need to syncronize that anti-phase with every vuvuzela that is playing so that every peak and valley would line up and cancel out?
justfoo2006 1 year ago
AGH!! MORIARTI!!
LithiumChicken 1 year ago
This has been flagged as spam show
Moriarty and Polikoff from President and Vice President!!
TheArmo1 1 year ago
I am trombonist too! BTW wrong aliqout.
Chmielok 1 year ago
Fuck ! How could you possibly not to love this guy ! He's like the Physics version of Professor Poliakoff
brilliantfranz 1 year ago 68
Any way you can make that .vi used in the video public?
millerkiller04 1 year ago
@millerkiller04 I've uploaded it at the following link, if you can decipher it!
nottingham-dot-ac-dot-uk-forward_slash-tilda-ppzpjm-forward_slash-Notch_filter.vi
If you can't navigate to this just send me an e-mail (Google "Philip Moriarty Nottingham" for my address).
Note that it's very basic and not particularly elegant code - I threw it together quickly for the video. National Instruments has a somewhat more sophisticated vuvuzela filter VI available from its website.
Philip
Moriarty2112 1 year ago
@millerkiller04 Ahem. That, of course, should be "tilde" rather than "tilda" in the link.
Apologies.
Philip
Moriarty2112 1 year ago
His filter would only work if all vuvuzelas were tuned more or less together. Real ones vary by about +/- 0.2 semitone, which makes filtering more difficult. Also, notch filtering can't get rid of people who can't play at all and make random noises, and people who are clever and figure out how to play the sub-octave tone.
Envergure 1 year ago
@Envergure
very true.
ethicks00 1 year ago
@Envergure, @ ethicks00::
Thanks for your comments on the video. @metabog raises exactly the point you make in a comment below. My response to metabog below also addresses your comments.
Best wishes,
Philip (person speaking in video)
Moriarty2112 1 year ago
i love u man.. ur cool
unknotmiguel 1 year ago
Lol, the anti-phase thing is such a misleading idea, it's impossible to always have the recorded vuvuzela constantly in anti-phase with some arbitrary vuvuzela sound in the background.
I also think it's much harder when there's a huge crowd of vuvuzelas with slightly (or considerably) different pitches (the bee-swarm noise), cause then it practically eats up a huge part of the spectrum, it's not just a few related harmonics.
This is why the vuvuzela is an acoustic tragedy!
metabog 1 year ago
@metabog It's also smack down in the middle of the human vocal range...
I wish there were more signal processing videos, like the Fourier one, but I know it's somewhat detached from general physics, but it's such an arcane and interesting subject with lots of applications.
metabog 1 year ago
@metabog Nice comment! Filtering out a single vuvuzela is indeed signficantly less challenging than trying to filter out a vuvuzela "chorus". The video was just to discuss the concept of filtering for those unfamiliar with the idea.
I can't think of an area of physics that *doesn't* involve Fourier analysis. One astronomer I know has said that it's "what physicists always do when they can’t think of anything better"! [Google "telescoper colour Fourier"].
Philip (speaking in video)
Moriarty2112 1 year ago
@metabog "An acoustic tragedy!" Love that phrase, think i'l borrow it thanks!
averilleX 1 year ago
Please do something special for your 100th video! :)
yoshinibble123 1 year ago
You guys could show how noise-filtering headphones work =D
ricardjorg 1 year ago
Aha, Audacity. Nice use of free software there.
suitov 1 year ago 2
Casimir effect next?
Vennificus 1 year ago
@Vennificus Nice suggestion! Coincidentally, I've recently been thinking about the Casimir effect for another potential Sixty Symbols video. "Stay tuned", it might appear at some point...
Philip (person speaking in video)
Moriarty2112 1 year ago
nice video. i'd like to see software that could accurately process recorded music of a band and transcribe the different music parts. that would be nice and save some time learning new songs :) however anything so far i've seen try to do this is pretty bad. i find it interesting how a musician good at listening can separate this out and write out the parts (or even identify the current 'chord' being played fairly easily, but to do it automatically seems very difficult.
chentiangemalc 1 year ago
lol
guthixftw11 1 year ago
Good god what an ear rape! It sounds much better/milder when I watch the actual match on tv.
alowfey 1 year ago
they shud bann them!!!!!!!
crazy4cars5764 1 year ago
my ears hurt... shouldnt have put it at max volume with a head phone....
jonting91 1 year ago
"Audacity" can do Anti-phasing if wanted FREE!!!
Films4You 1 year ago
Yes "Audacity" freeware is very, very good a sound editing, fitering and much more..
Films4You 1 year ago
@Films4You erm which function of audacity allows me to filter? im not very good at it...
XTrevvion 1 year ago
@XTrevvion YouTube, for the basic idea watch?v=KoPjxQW_7Rw
Films4You 1 year ago
Even we can filter out the annoying BZZZ from TV, we can't hear the cheering sounds and "we are the champion" song anymore....... Because no one in the stadium will attempt to do it
chakazul 1 year ago
The problem is that it works when all the vuvuzelas have the same lenght, but when you filter the harmonics of a wide variety of vuvuzelas the voice keep getting cut and cut.
aaronilai 1 year ago
I apologize If this is silly but why wouldn't the recording of the vuvuzela in anti phase create a case of deconstructive interference?
scilabo 1 year ago
you might as well put a beehive over your head to hear the sound of those vuvuzelas
takanoritoriyama 1 year ago
@takanoritoriyama Because people like listening to the cheering. That is at least the argument I heard.
Zeldakitteh 1 year ago
why do TV stations have to "filter" it out? why can't they just mute the input signals from the source or lower the volume and make the commentary's voice louder?
0501701 1 year ago
@0501701
That implies that the commentator is in a place separate from the ambient vuvuzela noise, ie in a studio in Tokyo, and not right in the middle of the stadium between the fans. Besides, TV stations might also be interested in getting a clear sound of the shoes hitting the ball and the referee's whistle which are impossible to record independently of the ambient noise.
arneperschel 1 year ago
Wouldn't different vuvuzelas and different players have different frequency values for the harmonics, potentially right across the spectrum - making the task of usefully subduing the noise more or less impossible for a large crowd of vuvuzela .. operators? (I think the term 'player' is possibly overdignifying what they do)
lonegroover 1 year ago
I enjoyed the brief explanation of harmonics. I would like to hear more about that.
ryanisflyboy 1 year ago
@ryanisflyboy There's lots more on harmonics and frequency spectra in the Sixty Symbols video on Fourier analysis.
All the best,
Philip (person speaking in video)
Moriarty2112 1 year ago
very interesting
alapunk13 1 year ago
What program is he using to do the notch filtering? It looks like LabView, but I had no idea it was capable of doing that.
bobbyt2012 1 year ago
@bobbyt2012 It is indeed LabVIEW. LabVIEW is ideal for frequency spectrum analysis and filtering because it combines simplicity and flexibility. (And no, I'm not employed by (nor receiving commission from) National Instruments!).
Philip (person speaking in video)
Moriarty2112 1 year ago
@Moriarty2112 Excellent to get feedback from you! I have access to LabVIEW, but I have no formal training in using it. I was trying to imitate what you were doing in Audacity with no avail. If you don't mind me asking, which subprogram were you using? Is there video or something that can teach me? Thanks again for all the work you put into this, it is extremely educational.
bobbyt2012 1 year ago
Comment removed
Moriarty2112 1 year ago
@bobbyt2012 I can e-mail you the LabVIEW "code" (i.e. virtual instrument (VI)) if you like. If you Google "Philip Moriarty University of Nottingham staff listing" you will find my e-mail address. Send me an e-mail and I'll send you the LabVIEW VI.
The first major task I had when I started as a lecturer in Nottingham in 1997 was to "re-vamp" one of our undergraduate laboratory courses so that it was based on LabVIEW. I hated LabVIEW initially but grew to love it.
All the best,
Philip
Moriarty2112 1 year ago
I thought the easiest way to filter out the vuvuzela was to hit the b*st*rd who's using it. Unfortunately that means hitting thousands of people but with team work we can do it people, who's with me? Yeeeeeeeeaaaaaaaaah!
Pazma1 1 year ago
@Pazma1 according to a leading Indian news paper, more than 1 mil vuvuzelas were sold in SA alone....... looks like there are a lot more than thousands of people to hit :)
09876124 1 year ago
@09876124
Dang, that's a lot of nuts.
Pazma1 1 year ago
Notch filtering works great, until they start manufacturing vuvuzelas with slightly different lengths. Also, if you start getting them in different frequencies, you'll also start getting beat frequencies off of them, making more notches required. Pretty soon the notches will completely cover the spectrum, and they become a fail as a solution.
puncheex 1 year ago
i've never had to adjust my volume so often for a single video, vuvuzelas rock
fnumb 1 year ago
Vuvuzelas are awesome!!!
majornewb 1 year ago
From what I've heard is that the anti-phase principle is being used in certain cars to make the motor sound less noisy, I doubt it can completely cancel out that noice. It's supposed to work in the cars and probably do.
Why would it not work for something like a vuvuzela?
FaintSnow 1 year ago
@FaintSnow: because you cannot control the frequency tightly - little imperfections and differences in dimensions cause the frequency to wander - and you can't control the phase. A motor is a single source; the vuvuzelas are multiple.
puncheex 1 year ago
what was the filtering program used? i noticed audacity but what is the other software?
ewigkase1 1 year ago
Search YouTube for "Vuvuzela Symphony". You won't be disappointed!
Kev888 1 year ago
This has been flagged as spam show
NIce, but a bit late, not merely because about 85% of the World Cup matches are history, but because none of it is news anymore nor is the content ludically educational. Just do a boolean "vuvuzela"+"filter". So, while I've never rated any of Sixty Symbols with thumbs down, this time I will.
DanHadan 1 year ago
@DanHadan well thanks for at least taking the time to explain your decision... it cushions the blow.
sixtysymbols 1 year ago 82
@sixtysymbols one whole dislike on this vid, you guys must be gutted
chillz27 1 year ago
@sixtysymbols Here is an article that explains what you did but without the science. gizmodo (dot) com/5563522/simple-software-can-filter-out-that-vuvuzela-whine-from-world-cup-broadcasts
warrmr 1 year ago
This has been flagged as spam show
@sixtysymbols
I'm sure that you're not looking for unconditional cheerleaders.
Keep up the good work!
DanHadan 1 year ago
@DanHadan You remain the only thumbs down
kieranRhunt 1 year ago
@kieranRhunt
As stated, it reflects that I've come to expect the content of Sixty Symbols' uploads to be, well, a few notches above this one here.
Hmm, if rating and comments are not disabled, should one, nonetheless, refrain from rating and explaining one's decision? κρι^τ-ι^κός , ή, όν ?
DanHadan 1 year ago
@DanHadan As the person speaking in the video, I'd like to respond to your thoughtful comments. You're absolutely correct, we don't want "unconditional cheerleaders". There are also many web pages which deal with vuvuzela filtering, as you say.
Our aim with this video was, however, to make the discussion as simple as possible so that those who had never heard of a notch filter or a frequency spectrum could get an insight into how the filtering works. Judge us on that criterion!
Philip
Moriarty2112 1 year ago
@Moriarty2112
Hi Philip,
Thank you for your reply. Please, do note that I started the initial comment with the term "nice" & that certainly encompasses keeping "the discussion as simple as possible so that those who had never heard of a notch filter or a frequency spectrum could get an insight into how the filtering works." My comment concerned timing (late) & lack of ludic aspect; rating and comments not being disabled, I didn't refrain from rating and explaining that rating.
Cheers,
Dan
DanHadan 1 year ago
@Moriarty2112
Hi Philip,
Thank you for your reply. Please, do note that I started the initial comment with the term "nice" & that certainly encompasses keeping "the discussion as simple as possible so that those who had never heard of a notch filter or a frequency spectrum could get an insight into how the filtering works." My comment concerned timing (late) & lack of ludic aspect; rating and comments not being disabled, I didn't refrain from rating and explaining that rating.
Cheers,
Dan
DanHadan 1 year ago
This has been flagged as spam show
@kieranRhunt
As stated, it reflects that I've come to expect the content of Sixty Symbols' uploads to be, well, a few notches above this one here.
Hmm, if rating and comments are not disabled, should one, nonetheless, refrain from rating and explaining one's decision? κρι^τ-ι^κός , ή, όν ?
DanHadan 1 year ago
How about using the noise sample feature in audacity, maybe that would work better than notch filtering. take a 10 second sample of just the vuvuzela, and apply that filter to the (voice/vuvuzela) combination. I haven't tried it myself however it's worth a shot :)
BoogabooMusic 1 year ago
VUVUZULA WUUUT
kiIIamaim 1 year ago
Great video, proud to be a part of this university :)
Also, a big audacity fan. :)
ItsOnlyDavid 1 year ago
loved this video.
useyourdelusion 1 year ago
Hah way to stick in random clips of vuvuzela performances. ;)
smbhax 1 year ago
Awesomesauce.
JonnMcNally 1 year ago
worst.instrument.ever.
Rib640 1 year ago
What software is being used to get the frequency spectrum?
n4oliver 1 year ago
I hate those instruments.
lovingboarding 1 year ago
Great stuff.
Intervene 1 year ago
Id love to see more vidoes about sound-theory, since im a hobby producer this was really interesting to me
Xayo 1 year ago
nice explanation thank you.....
ranjanunmvj 1 year ago
Was he using PSpice or LabView or something else for the frequency analysis?
Jmoges 1 year ago
Someone should combine vuvuzelas with autotune. The two greatest contributions to sound from humankind.
culwin 1 year ago
@culwin I hope you're being sarcastic.
Wildcard1992 1 year ago
@culwin ha ha - good comment mate!
jeebersjumpincryst 1 year ago
@culwin Check out MysterGuitarMan's channel; he made a video in which he played loads of vuvuzelas and autotuned the drone into a pice of classical music!
Kev888 1 year ago
Audacity... It really is a nice piece of Open Source Software.
ThatGuyFromAustria 1 year ago 59
@ThatGuyFromAustria No, It's labview.
peterbriers 1 year ago
ooh so thats a vuvuzela....thank you dear for that explanation, for myself personally , my only reaction would be to say that i remember there used to be a medication which came in a tube with a nozzle on it that the doctor would prescribe you for the treatment of hemorrhoids, suffice it to explain how the medication and the vuvuzela would be correctly and preferably used....they even look alike save for the difference in dimensional scale,and they are both painful when employed in proper manner
777Marlene 1 year ago
Very interesting
ByakuyaZERO 1 year ago
Vuvuzelas sound like a fog horn. They're annoying because the single pitch is boring.
Austyg 1 year ago
Why not just stick the commentators in a sound proof room? that way there wont be the sound of the vuvuzela, just the commentators!
MattLiViD 1 year ago
@MattLiViD Even then, they still are recording from the football pitch, so unless you don't want to hear the crowd and the cheers and the soccer players and the referees, there is always going to be that incessant drone.
Wildcard1992 1 year ago
Finally, a video for us sound engineers!
jgordon707 1 year ago
This has been flagged as spam show
Small technical complaint: the diagram at 0:40 shows the wrong harmonic structure. The fundamental harmonic shouldn't be node to node, but antinode to antinode. This is due to the fact that it is open at both ends. This gives the same pattern of frequencies, so for the most part it's a distinction without a difference, but still.
odysseus9672 1 year ago
@odysseus9672 --- Pressure nodes are displacement antinodes, and vice versa. But you're right - I should have more carefully explained this. The diagram at 0:40 shows pressure nodes at the ends of the tube. If it were drawn for displacement then you're correct, they would be antinodes.
Philip (person speaking in video)
Moriarty2112 1 year ago 2
@Moriarty2112 Ah, indeed. Thank you. :)
odysseus9672 1 year ago
What was the Audacity plug in you used?
Alhoshka 1 year ago
@Alhoshka --- All recording was done with the basic version of Audacity (ver 1.2.6) - no additional plug-ins required. However, the spectral analysis was done with LabVIEW, not Audacity.
Best wishes,
Philip
Moriarty2112 1 year ago
Nice, Audacity :D!
Dan4157 1 year ago
God I wish they wouldn't blow those damn things, they make the entire world cup a pain to listen to.
turdbutt89 1 year ago
Audacity! :)
1RadicalOne 1 year ago 2
I've always compared the noise to an F1 car at idle...
JimPrower 1 year ago
Can't you make a new "anti-sound" for every specific occasion? One mic for the reporter and one or several for the immediate surrounding? Or place the reporter in a concrete bunker at a nearby moon?
Rasayana85 1 year ago
lol i am the 306 th viewer on 3 vids tpoday xD
MacMillanSniper 1 year ago
@MacMillanSniper
Seems like my numbers are incrementing with each comment. Last video was the 305th comment, now 306th... lol.
FmMan33 1 year ago
@MacMillanSniper
Because view counts get stuck. Says everyone is the 306th viewer, including me.
revender13 1 year ago
@revender13 it doesn't get "stuck." It just updates once every couple of hours.
Carutsu 1 year ago
@Carutsu
Right... So it's stuck on 306 until it updates, idiot.
revender13 1 year ago
This has been flagged as spam show
Pfft, everyone knows all you have to do is type
:stopsound:
jmbishop511 1 year ago
technically isn't it the first harmonic, then the third, then the fifth harmonic?? its a tube with a closed end......standing waves can only produce 1,2,3,4... harmonic waves.
LilReaper1010 1 year ago
@LilReaper1010 Thanks for raising this. The harmonic spectrum for trumpets and trumpet-like instruments is more complicated than you might think. Google "hyperphysics brass" for a discussion - I found this web page very enlightening.
The vuvuzela is also conical which in principle means its spectrum should be like that of an open tube. In any case, in the video we see harmonics at 220 Hz, 440 Hz, 660 Hz etc... i.e. fo, 2fo, 3fo (where fo is the fundamental) and not fo, 3fo, 5fo....
Philip
Moriarty2112 1 year ago
Can you explain why the anti-phase idea wont work?
Easwarvasi6 1 year ago
@Easwarvasi6 There has to close synchronisation of the original signal and the cancellation signal in order for it to work. This is why noise cancelling head-phones incorporate a microphone - a phase-shifted version of the sound is applied in "real time". There is no way that a recording of the vuvuzela drone from another World Cup game is going to synchronise with that from a different match. There's also the issue of the placement of the "anti noise" source...
Don't buy the software!
Philip
Moriarty2112 1 year ago
@Moriarty2112 The anti-phase is similar to how the double slit experiment will not work with two sources, one would have to use one source (because two different sources would never be in phase)?
Zeldakitteh 1 year ago
@Easwarvasi6 I think it's because for waves to cancel, they have to be positioned exactly on top of each other, which is nearly impossible if you have waves coming from hundreds or thousands of vuvuzelas.
calvinhobbesliker2 1 year ago 3
@Easwarvasi6
1. the anti-wave will never correctly "align" simple by playing another sound. If it were that easy, just a second Vuvuzela in the stadium would cancel it out.
2. you have not one but many Vuze's. For everyone you would have to play an anti-wave, because their phase is not in sync.
3. although one Vuze may have very distinct frequencies, just a slightly different build will make another frequency. You would need an anti-wave for every possible Vuze (also problem for notch filters)
superdau 1 year ago 2
@Easwarvasi6
how should you be able to make such an mp3, wichtout knowing exactly how the vuvuzelas will sound like at a given time and exact location in a stadium IN THE FUTURE? its a bit like the wireless network cables they sell on ebay, where you get literally nothing if you buy them, except that in this case you just get vuvuzela sound.
kurtilein3 1 year ago 2
@kurtilein3
Not only that, you'd have to know the exact moment when to start playing it, down to the nanosecond, possibly even more accurately in order to even cancel one properly.
LinkStrikesBack 1 year ago
Of course the football audience will have thousands of vuvuzelas, possibly none of which make quarter as stable a note as your trombonist does. :)
gwaur 1 year ago
Audacity is such a cool piece of software,
Especially since it is completely free
fossil98 1 year ago
@fossil98 Entirely agree - I love Audacity and it was by far the easiest way to capture the samples of the vuvuzela. However, the only thing I don't like about it is that it's not easy to isolate and zoom in on particular regions of a frequency (Fourier) spectrum. That's why LabVIEW is used for the spectral analysis in the video.
Philip Moriarty (person speaking in video)
Moriarty2112 1 year ago