Sonic Assassins

russiawave

In a developing mystery, Associated Press is reporting that US diplomats stationed in Cuba are complaining about ‘health attacks’ which appear to be linked to some kind of odd sound phenomenon. The incidents have taken place both in the homes of the diplomats and in hotels, and are said to be “confined to specific rooms or even parts of rooms with laser-like specificity”. One victim reported experiencing the ‘agonizing’ sound only in his bed; when he walked to the other side of his bedroom, it was completely absent.

“In several episodes recounted by U.S. officials, victims knew it was happening in real time, and there were strong indications of a sonic attack.”

The episodes seem to take the form of “vibrations and loud ringing or a high-pitch chirping similar to crickets or cicadas” and a “blaring, grinding noise”. So far, doctors have examined 21 affected Americans, diagnosing them with mild traumatic brain injury (or concussion) and permanent hearing loss. Some victims now have problems concentrating or recalling specific words, and other symptoms include brain swelling, dizziness, nausea, severe headaches, balance problems and tinnitus, or prolonged ringing in the ears.

Puzzlingly, some people have reported some of the symptoms, but have not heard unusual sounds of any kind.

Speculations that some kind of ‘sonic weapon’ has been brought to bear are hard to substantiate. Devices that might cause these kinds of effects using only sound are not known to exist, and even if they did, they would be large and require a considerable amount of power – not the kind of thing you could sneak into someone’s house unnoticed.

“Brain damage and concussions, it’s not possible,” said Joseph Pompei, a former MIT researcher and authority on focussed sound technology. “Somebody would have to submerge their head into a pool lined with very powerful ultrasound transducers.”

So what’s going on? Have malevolent anti-US agencies discovered a new quirk of physics that they’ve deployed into a frightening sonic brain laser? Is it a manifestation of collective obsessional behavior? Or is there some more mundane explanation that has yet to be uncovered?

Stay tuned, we’ll keep our fingers on the pulse of this one.

Advertisements

The Sound of Silence

saturn2

In two days, as of this writing, one of the greatest scientific adventures of all time will come to a close. I am, of course, talking about NASA’s extraordinary Cassini mission. Launched amid controversy* in 1997, and arriving at Saturn in 2004, Cassini’s primary mission was to observe the ringed planet and its moons for 4 years. It exceeded expectations, and after completing its main objectives, continued to return groundbreaking science for almost a further two decades. Now, its power supply is reaching depletion, and the mission team have decided to terminate the life of the spacecraft while they still have it under their control. To avoid the unlikely – but still possible – contamination of Saturn’s water-bearing moon Enceladus by Earth microbes that may have hitched a ride on the vehicle, its orbit has been changed to plunge it into Saturn’s atmosphere at an oblique angle on September 15. It will be incinerated in seconds.

Anyone with an ounce of imagination can’t fail to have been awestruck by the amazing high definition real-colour images that Cassini has beamed back from the edges of Saturn’s rings. We’ve also marvelled at the many extraordinary hidden features revealed by the craft’s ability to see into the infrared and ultraviolet.

Something that is less known, however, is that Cassini also captured many of the sounds of Saturn and its moons.

cassinisound1

Now, there is no sound in space, as we all know, since there’s no atmosphere to conduct it, and Saturn’s ‘sounds’ are actually not the kinds of things we could hear with our ears anyway; they are formed from magnetic fields, and from radio and plasma waves captured by Cassini’s magnetometer and RPWS (Radio and Plasma Wave Science instrument). In order to make them audible to a human ear, the mission scientists have taken these very high frequency emissions and dropped them down in pitch to bring them into the audible spectrum, and then time compressed them, so that events that happen over many minutes or hours, are revealed in seconds.

You should not think this is a fanciful pursuit, undertaken by geeks in order for the audio nerds to boast as much as the imaging team. Instead of being merely quirky, sound recordings made in this way can actually reveal useful data about Saturn that cannot be ‘visualised’. We know, for example, that Saturn’s auroras sound similar to the auroras of Earth when rendered in this manner, as do lightning storms. These ‘sped-up’ sound snapshots also provide insights into the rotation of the planet and the movements of its moons that cannot be easily grasped in other ways.

You can hear some of the strange and beautiful sounds of Saturn here, along with a few musical works made by composers inspired by them.

One thing I should note is that there was, in fact, some ‘human audible’ sound returned from the Cassini mission, and that happened quite soon after the spacecraft’s arrival in the Saturn system in 2004. As Cassini passed Saturn’s largest moon, Titan, it launched its probe Huygens down to that world. Because Titan actually does have an atmosphere, Huygens was fitted with microphones designed to capture actual audio frequencies. If you’d been on that probe, this is what your human ears would have heard.

In two days, Cassini will go silent. In spite of all the astonishing visual material that Cassini has beamed back to us over the decades, we will still use a sound metaphor to convey the idea that communication from it has forever ceased.


*Cassini is powered by a nuclear power source fuelled by plutonium-238. At the time of its launch, people who didn’t really know much about science freaked out about this for reasons that are hard to understand.

Compression Depression

sadmusic

“Research finds MP3s make your music sound more depressing” says the latest bit of breathless reportage to come floating down the audio/science news feeds. In this new ‘post fact’ age, I guess I’m no longer supposed to be surprised by the paucity of actual evidence offered up in support of any particular assertion put forward as scientific ‘research’ but in the interests of actual reality, let’s focus the Hummadruz lens on this affair.

As usual, nearly every mention of this that I saw completely uncritically regurgitated copy that looked like it came from one source. I couldn’t narrow it down to a first instance, but the coverage from NME was typical:

New research has found that listening to music in low-quality digital formats can dampened its emotional impact.

According to a study by the Audio Engineering Library, MP3s can have a distinct effect on the “timbral and emotional characteristics” of the instruments involved.

Researchers compared responses to compressed and uncompressed music over ten emotional categories at several bit rates.

It’s always instructive to find out who is responsible for research, so my obvious first action when I read the above quote was to click on that link to the ‘Audio Engineering Library’ and find out who those dudes actually are. Puzzlingly, the link just leads to the abstract of the actual paper, which makes no mention of that organisation.

In fact, searching the web for the ‘Audio Engineering Library’ reveals that there is no such entity, and, instructively, pretty much every search result leads to some variation or other of the story about ‘How compression makes your music depressing’. It’s a veritable self-referential maelstrom. Audio Engineering Library? Someone just made that shit up.*

If ever there was an indication that we are about to enter the land of hogwash and horsepiss, here we have it.

Still, we have the paper right? Published on Researchgate – the science industry equivalent of LinkedIn – to be sure, but proper science will out!

The first thing we should note is that this research is a one-off  publication, on an online site, of a conference presentation. The research it entails has neither been replicated, nor peer-reviewed. This is, in scientific terms, not much more than a bunch of opinions.

We don’t have to delve far into the paper to find its true worth:

3.2 ListeningTest

We used eight sustained instrument sounds: bassoon (bs), clarinet (cl), flute (fl), horn (hn), oboe (ob), saxophone (sx), trumpet (tp), and violin (vn).

Whoa there cowboy! I was told by NME that the compression made my music more depressing. You do know what music is, don’t you NME? What it is not, is a bunch of fixed-note sustained instrument noises taken entirely out of musical context.

In addition to that complete clanger, there is no mention anywhere in the paper about how many subjects were used in these tests, nor anything about how they were conducted – just a lot of technical hocus-pocus about compression methods, and some graphs that are totally meaningless given what we just read. Wading further through this procedural mess, we find so much experimenter subjectivity stirred into the mix that the study is rendered all but useless as a piece of viable science.

To sum up, an unpublished, un peer-reviewed paper, conducted by a fictional institution,  tells us that in an un-replicated study, an unspecified number of listeners (keeping in mind that could be as few as two) were played compressed timbral instrumental single tones (not music) and asked to subjectively choose – from a list pre-determined by the researchers – how those noises made them feel.

Would you conclude that from there you could get to “Research finds MP3s make your music sound more depressing”?

No, me neither.


*Addendum: It seems they probably mean the AES (Audio Engineering Society) Library, where the paper is also archived. So let’s chalk that one up to sloppy journalism, rather than wilful deception. On the AES site, the presentation appears under its actual title The Effects of MP3 Compression on Perceived Emotional Characteristics in Musical Instruments [my emphasis].

Notice that this doesn’t make any claims about music, per se, and is a much more accurate appraisal of what the study was actually looking at (see comments below for further clarification).

It’s Just Not Crickets

I’ve noticed that a rather old piece of ‘science’ trivia is floating around the social feeds again, and I thought this might be a good Hummadruz opportunity to dispel the myths surrounding it once and for all.

The story is this (as reported breathlessly on many incredulous sites but in this case we’ll be using text from truthseekerdaily.com):

Composer Jim Wilson has recorded the sound of crickets and then slowed down the recording, revealing something so amazing. The crickets sound like they are singing the most angelic chorus in perfect harmony. Though it sounds like human voices, everything you hear in the recording is the crickets themselves.

Here’s a version of the the recording on Soundcloud:

What you’re hearing is the supposed slowed down crickets, with the original speed crickets layered over the top. It certainly does sound eerie and somewhat choral. Amazing huh? The reportage of this phenomenon is frequently accompanied by this endorsement by Tom Waits:

Tom Waits (on Jim Wilson): “Wilson, he’s always playing with time. I heard a recording recently of crickets slowed way down. It sounds like a choir, it sounds like angel music. Something sparkling, celestial with full harmony and bass parts – you wouldn’t believe it. It’s like a sweeping chorus of heaven, and it’s just slowed down, they didn’t manipulate the tape at all. So I think when Wilson slows people down, it gives you a chance to watch them moving through space. And there’s something to be said for slowing down the world.”

The hyperbole that goes with the piece almost invariably makes much of the claim that the slowed down crickets are not altered in any way apart from the direct change in pitch, but is such a claim believable?

As a professional sound designer and composer of nearly 40 years experience, I’ve had a quite a bit to do with the sounds of crickets in my time. I’ve composed several works comprised of manipulated insect and bird sounds, and I’ve spent many long hours on numerous projects building unusual atmospherics from crickets and frogs. I know cricket sounds better than most people on the planet.

And the sounds in that clip from Jim Wilson don’t sound like merely slowed-down crickets to me. But hey, you don’t have to take my word for it. Let’s do some science!

Since the clip includes the sounds of crickets running at normal speed layered over the top of the slow ones, then it follows that we could just slow the whole thing down again and get the same effect, right? The low crickets would drop right down out of audible range, but the normal speed crickets would themselves become the magical choir sounds. So let’s try it:

Hmm. Just a single low tone. No three part harmonies there, nor any beautiful modal intervals like in the Jim Wilson version. To me this is not so surprising, because I’ve used this technique a thousand times – slowing crickets down inevitably delivers you a single tonal version of the original. Sometimes you might get rhythmic pulsing, or grinding noises, but that’s about it, and it’s always at one constant pitch.

If you know anything about how crickets make their sounds, none of this will be  surprising to you either. Like most insects that generate some kind of chirruping or rasping or droning sound, crickets use a mechanism called stridulation to create their loud noise. This is one of the most basic ways that a sound can be generated: friction of one body part rubbing on another creates vibration. It’s essentially a variation on the effect you get by running your fingernails up and down a washboard.

Insects can achieve stridulation in a variety of ways, but in nearly all cases, they will, through limits of their anatomy, achieve just one basic pitch, or ‘note’ – just as we’ve seen in the slowed-down example above. For them to be yielding complex melodic structures like those in the Jim Wilson track, requires an explanation that I’m sure you will find as irksome as I do: that different crickets are making different pitches and that they’re then co-operating to create choral masterworks in human melodic modes. Specifically in Western liturgical scales, at that. If that’s what’s going on here, then there are at least a half dozen major scientific discoveries waiting for an enterprising biologist to claim.

The truth is well to the contrary. When you hear insects making noise, they’re far from being co-operative. They have no interest at all in harmonising with their pals to sing the glory of God. They are in fact competing with one another. Aggressively. For sex. The loudest and most impressive gets the prize. That is all.

So, how do we explain, then, the eerie vocal harmonising in the Jim Wilson recordings? In my opinion, as a composer and performer who is very accomplished in these techniques, the answer is completely obvious. The simple, single note tonal drones of crickets lend themselves perfectly to being raw material for a popular modern instrument: the sampler. With a music sampler, a sound can be tuned across the musical scale in such a way that it can be played on any note desired. I believe that Jim Wilson has taken the monotonal cricket sounds as his basic building blocks and then played whatever melodies and harmonies he wanted with them.

There’s nothing wrong with doing any of that, of course – there have been some wonderful musical explorations of this idea – but to promote it as some unexplained natural phenomenon with supernatural overtones is at least irrational, or at worst, exploitative.* And disappointingly human-centric.

The unadorned sounds of the natural world are beautiful in their own right and there is really no need to invoke human notions of value for them to be emotionally powerful. Learn to listen to those sounds for what they are. Here is a good starting point: the wonderful natural recordings of my good friend Andrew Skeoch through Listening Earth.


*Jim Wilson sells these recordings under the title ‘God’s Chorus of Crickets’. It is important to note that he himself does not anywhere make the claim that the recordings are just slowed down. To the contrary, these are his own words: “I discovered that when I slowed down this recording to various levels, this simple familiar sound began to morph into something very mystic and complex...”  The ‘various levels’ he’s talking about are chromatically tuned intervals. But he’s certainly not – as far as I’ve seen in my broad investigations – actively contradicting the numerous sites that claim the sounds have not been manipulated.

Clarity

dog

In recent times a number of devices have appeared on the market that promise to deliver a better musical experience than the one you usually receive from your portable digital music player of choice. One such gadget was brought to my attention yesterday – it goes by the name of the Chord Mojo.

“Simply connect Mojo to your iPhone, Android phone, PC, or Mac,” says the site, then “plug in your headphones and you can experience crystal clear audio the way you would hear it in the recording studio.”

So what’s the deal? Can this £300 (US$430) box really deliver on that promise?

Well, maybe. Like so many things in the shadowy world of audio snake oil, the claim comes with some caveats which the manufacturers assiduously avoid bringing to a potential customer’s attention.

The Mojo is what is called in the business a DAC, or Digital to Analog Converter. As you are most likely aware, the music on your portable music device is stored as digital bits. Those bits need to be converted into analog sound waves for them to be heard by your ears. Your musicpod obviously already does this – otherwise you wouldn’t be able to hear anything – but gadgets like the Chord Mojo claim to be able to do it better. To achieve this marvellous feat, the digital-to-analog converter and headphone amplifier circuit on the musicpod is bypassed altogether, and the (bulkier than an iPhone) Mojo plugs into the USB or Lightning socket on your device. You then plug your headphones into the  Mojo, which does the heavy lifting of converting digital bits into analog audio and then amplifying it (in a presumably more-sophisticated way than the DAC in your iPod).

But does it do what is claimed on the box? Probably, in a technical sense, yes. The real deception with products like this is elsewhere, so we have do a little sifting to find where the truth actually lies. Take that sentence from the website: “…crystal clear audio the way you would hear it in the recording studio.” That’s an amazing pledge – is that really what you could expect if you just plugged it into your iDevice straight off the shelf?

I doubt it. The truth is that this promise is based on something that the makers of the Mojo neglect to mention: it all depends on how your music files are made. If, like the great majority of people, your files are compressed into mp3 or AAC file formats, it’s simply a lie. No DAC, no matter how good, is going to make your mp3s sound like ‘audio the way you would hear it in a recording studio’. It’s even a highly contentious claim, in fact, to say that it would necessarily make your compressed music sound any better than the DAC already present in your music player does.

Now, if you happen to carry all your music around uncompressed (and I know absolutely no-one who does that – not me, nor any of my very experienced audio professional friends), you might benefit from a better DAC than the one in your iPod. Might. Because this would also depend on other factors, one of those being that a pair of Sony ear buds (like the ones in the promotional photo on the Chord Mojo site) would not aid you in this pursuit. In other words, a great deal depends on the quality of the headphones you’re using; tiny ear buds, no matter how good, will not deliver you ‘audio the way you would hear it in a recording studio’.

What the Chord Mojo site – and indeed, most other sites selling these portable DACs – leads an unknowledgeable reader to assume is that buying this expensive gadget and simply inserting it in their normal setup will give them better sound.

It won’t.

Hummadruz advice: If you really care about your music sounding better, just listen to it off CDs, or make uncompressed digital versions. And, if you do happen to have a cool $400+ burning a hole in your pocket, invest in a decent set of headphones.

Mercurial

freddie

“Science Confirms That Freddie Mercury Was Basically The Most Amazing Singer Of All Time” screams one headline. “Freddie Mercury Is The Greatest Singer Of All Time, Because Science Said So” says another. “Queen’s Freddie Mercury Had One Of The Best Singing Voices Of All Time, According To Science” gushes a third. I’m sure you saw them in your social media feed in the last week or so.

So what’s the story then? Have scientists come up with some amazing new method for applying empirical assessment to artistic subjectivity? Has scientific endeavour somehow managed to ‘confirm’ that Freddie Mercury is indisputably the most accomplished singer in human history?

Well, as you might have guessed, not so much.

Let me say from the outset that, by a considerable agreement of subjective reckonings, Mercury is an amazing singer. His vocal prowess is all the more extraordinary in light of his lack of formal training; he was self taught instrumentally and vocally, and claimed not to be able to read music. We really don’t need science to be able to legitimise his talent, per se.

And indeed science is not even attempting to do any such thing. The hyperbole above is generated by the lamest corners of the social media press, after the recent publishing of a paper by Christian T. Herbst et al, from the Faculty of Science at Palacký University, Olomouc, in the Czech Republic. Herbst frames the intentions of the research like this:

“The purpose of this study was to conduct a viable analysis of publicly available data material, in order to arrive at more empirically based insights into Freddie Mercury’s voice production and singing style.”

So the researchers, who self-describe their work as ‘fan science’, take it as a given that Freddie is an awesome singer and are simply gathering some data to help understand – in a technical way – how he did his stuff.

To do so, they examined both his speaking and his singing voice, concentrating on its timbral qualities, vocal range, vibrato and vocal subharmonics. In addition, they had a trained singer emulate some of Mercury’s vocal stylings and observed the active vocal cords with an endoscope. It is all fairly fascinating in its own right, and the breathless exaggeration from some sections of the interwebs really does the science no favours.

So what do the results of their efforts tell us? Well, not a lot that an experienced singing teacher couldn’t have concluded just by listening, in all honesty. They found that Freddie’s vocal style encompasses a remarkable variety of techniques, including a faster than average vibrato, the occasional use of vocal subharmonics (mostly to add a growl or burr to his voice) a proficient control of phonation and an impressive vocal range (although not quite the four octaves often claimed).

The paper provides empirical details of all these things, although, surprisingly in my opinion,  not much investigation into Mercury’s falsetto, which was one of his most dramatic vocal accomplishments (Mercury showed an almost incomparable ability to elide from his upper vocal register into falsetto and back again with virtually no audible transition – singers will tell you that this is very difficult to do).*

So to sum up, we already knew that Freddie Mercury was a pretty astonishing singer. What this investigation does is shed a little bit of scientific light on how he did his thing. What it does not do is ‘prove’ anything about his standing in the dominion of wonderful singers through the ages. And truly, that task is simply not the concern of science.

You can read the full technical paper ‘Freddie Mercury—acoustic analysis of speaking fundamental frequency, vibrato, and subharmonics’ here.

 


*You can hear many examples of this in the early Queen albums Queen, Queen II and Sheer Heart Attack. It is notable on the songs Lily of the Valley, Nevermore and The March of the Black Queen. Mercury’s use of the technique diminished as the band became more conventionally ‘rock’ oriented in later years.

Noise Cancelling Shnozphones

Yesterday a friend sent me a link to this crowdfunder on Indiegogo, with the appended question: “This has to be ludicrous BS, right?”

The alleged ludicrous BS is a device called Silent Partner which claims to ‘quiet snoring noise’ (we’ll examine those exact words in a bit) through the mechanism of Active Noise Cancelling (or the popular acronym ANC).

You will be familiar with ANC if you’ve ever worn a pair of noise-cancelling headphones on a plane. Pop those suckers on, and the sound of the plane vanishes almost magically. You can actually hear the in-flight movie soundtrack.

The technology behind those headphones is really quite simple, and has been known for over half a century. In this post we’ll delve a little into how noise cancellation works, what it’s used for, and why Silent Partner is almost certainly BS. Not as ludicrous as it first appears perhaps, but let me just say that I’m not pitching in to the Indiegogo campaign any time soon.

The Acoustic Principle Behind Noise Cancellation

As you probably know, sound propagates through a medium via waves. Most people have seen graphic representations of soundwaves these days. They look something like this:

Screen Shot 2016-03-10 at 11.11.53 AM

That’s a fairly complex soundwave. The simplest manifestation of a sound is a sine wave. This one represents a pure tone, like you might hear if you strike a tuning fork:

sineposgraph

The red bar shows you the frequency (pitch) of the sound and the green bar marks out the amplitude (loudness). I’ve marked the highest and lowest amplitude with an arbitrary value to aid explanation. One thing to understand – and is easy to see in this simple sine wave – is that as a wave propagates, it changes its amplitude value across the zero axis; there is a time when the amplitude has a positive value, and a time when it has a negative value. This is called the phase of the wave, and this is true of all waves, not just sound waves. So in this case, the frequency of the sound stays exactly the same (a constant pitch), but the amplitude is wavering between positive and negative, as it does in all sound waves.

You can’t hear this constant amplitude change. You are only aware of the overall amplitude between the peak and the trough of the sound – this is the volume, or loudness, of the sound.

Somewhere, some time ago – no-one really knows when, but we can guess it was likely to around the beginning of electronic sound recording – someone discovered that it is possible to artificially ‘flip’ the phase of a recorded sound wave.*

sineneg2

Here’s the thing: this flipped sound wave will sound to your ear exactly the same as the one we depicted above. EXACTLY. If I played them to you one after the other, you would not be able to tell which one was which. However, if we artificially combine both these waves so that they are coherent – that is, they start at precisely the same time, and stay in step with one another – then the positive value of the first peak of the sine wave is completely cancelled out by the negative value of the first trough of its phase-reversed counterpart. It’s just simple mathematics: you add +1 to -1 and you get zero. The result is total silence. The positive ‘loud’ bit of one wave totally cancels the negative ‘loud’ bit of the other.

The first time this was demonstrated to me as a sound student, I was astonished. It seems like a weird kind of audio magic. Nevertheless, it’s just a property of wave mechanics, and we use this phase cancellation trick in numerous different ways in the pro audio business.

How Does Phase Cancellation Work in ANC Headphones?

Even though we’ve been looking at an example of a pure sine wave, phase cancellation works on any complex audio wave you care to submit to it. You take a recording of Kanye West, flip it out of phase and recombine it with the original and zap, perfect silence. An exemplary case of nature balancing itself for the better good.

The only condition is that the two waveforms must be completely in step with one another – coherent.

One day it occurred to someone that it might just be possible to accomplish this trick in real time, with live sound. This is how it would work in theory: you’d aim a 180º out-of-phase microphone at a sound and pump it through a speaker in the vicinity of the actual sound. The amplified phase-inverted sound would interact with the real sound and cancel it out. And indeed, it does work. Sort of. It’s very dependant upon where the listener is positioned in respect of both the phase-inverted source and the real sound. Too close to one or the other and the necessary coherence between the two sounds gets out of step. The effect completely vanishes. It works, then, as long as you tell your listener to sit exactly there, and don’t move your head even the tiniest bit. Not particularly satisfactory for most practical purposes.**

If only you could stick the inverted phase sound right at the listener’s ear drum, where it would arrive at precisely the same time as the real life sound… and of course, you can do almost exactly that, providing that the listener is wearing headphones.

So ANC headphones have a little microphone on each earphone, which captures almost the identical sound that is heading toward your eardrums. That sound is then amplified to the exact same amplitude as the original, and inverted in phase. It arrives at your eardrum at the same time as the real sound, effectively cancelling it out. It’s a very cool trick, but it’s highly reliant on the microphone and the speaker diaphragm being very close together, and both those things being as close to your eardrum as is technically – and biologically – feasible.

That All Sounds Plausible! What’s the Problem with Silent Partner?

This is where things get a little more complex than they have been so far, but you already know most of what you need to know to follow me.

I’m speculating that this is how Silent Partner is intended to work: the sound of the sleeper’s snoring is picked up by some microphones – I assume this is what is designated as the sensor in the rather lite ‘technical specifications’. The captured audio is then phase-inverted, amplified and played back through the speakers and ‘resonance chamber’, where it presumably combines with the sound of the actual snoring with the intention of cancelling it out.

You can see one big problem already: as I’ve mentioned above, the most effective sound cancelling happens if the coherent waveforms arrive as close to the listener’s ear as is achievable. In this case, we have something of a distance between the snoring source and the beleaguered sleeping partner – plenty of distance for the waveforms to dis-cohere, and also plenty of distance for another wave-related phenomenon to come into play. I’m talking here about polarisation. Without getting too technical about it, waves are not just two-dimensional like the representations in the graphs above. They are fully 3D, and so for exact noise cancellation to happen effectively, the waves and their anti-phase cohorts must be fully coherent in those three dimensions. This is really hard to achieve in a real-world environment, even with precise, point-source sound. It’s especially hard to achieve when you consider the nature of snoring, which doesn’t actually come from just the nose, as anyone who’s slept with a snorer knows. So, even in the best possible technical case, with the Silent Partner reproducing the snoring sound in every tiny detail of frequency and amplitude, it’s not going to be aligned in proper polarity and coherence with the sounds coming from the nose, throat and chest cavity of the snorer. It just can’t be.

The first clue we have that the makers of Silent Partner are either unaware of this issue (odd, since they supposedly trialled a proof of concept in May 2015), or worse, are being disingenuous about it, is in the video clip. It pertains to their demonstration of the ‘Silent Zone’ around the snorer. In the clip you see a ‘scientist’ holding a decibel meter close to the nose of the snoring person, and showing how the sound level drops as you get further away. Well, yes, this is exactly what you’d expect with normal snoring – sound falls off with distance according to the well known properties of the Inverse Square Law. But this is not what you’d expect to see if the Silent Partner was working as claimed. What you’d actually observe is no change in the sound level. The noise-cancellation effects should be in play – and in fact optimal – right at the source of the snoring. The sound level test in the video is showing us nothing at all but what you’d expect to see with natural snoring.

In fact, the whole meter thing is quite amusing if you know anything about sound. If the meter is measuring decibels (and I’ve no reason to think that it’s measuring anything else – that’s what sound level meters usually use) it’s showing that the snoring volume is dropping from about 84dB to 60dB. To give you a sense of that in terms that might be more familiar, that’s about the level of noise in a moderate factory or a busy road, down to the level of a normal conversation. I’d expect average snoring to have less effect on a dB meter! It’s certainly not an endorsement of a Silent Partner working as claimed.

And all this assumes, as I said, a best-possible case: that the Silent Partner is exactly reproducing the snoring sound. I’m skeptical that it could do even that. Snoring is made up of highly complex human sounds, and is not just one rhythm or frequency. And, as I’ve also pointed out, it doesn’t just come from the nose and mouth, so the entire upper body can contribute to the frequency characteristics. I would be very surprised if tiny components such as those in the Silent Partner – even with resonance chambers – could deliver an acceptable frequency response to enable the kind of phase and frequency matching required for this technique to work.

Aside from all the sound stuff, something just feels really fishy about this whole thing. First of all, the snoring-relief market is chock full of pseudoscience, which indicates an area of high subjectivity and therefore exploitable credulity. You can get anti-snoring pills, anti-snoring rings, anti-snoring pillows, anti-snoring homeopathy, anti-snoring acupuncture and so on and so on, none of them based on even the most delicate whiff of science. So it’s a field rich for the pickings, as they say.

Furthermore, Silent Partner deploys a technique beloved of purveyors of said pseudoscience: it piggybacks on something that to the layperson sounds credible and possible, but brushes a lot of actual dirt under the Carpet of Mystery: “It’s like magic!” boasts the hyperbole – a claim which is actually probably quite true, because it would be magic if it worked, since it defies the laws of physics. Like many pseudoscientific gadgets and gew-gaws, it fails to provide any real science to substantiate its claims, just a lot of hints at how it might work based on other things that do work. ***

There are many other red flags:

• The Silent Partner website is full of exhortations to Order Now! I don’t know about you, but for me this may as well say Give Us Your Money Quick, Before The Truthful Reviews Start Rolling In! Although the Indiegogo timeline includes a proof-of-concept as of May 2015, there is no indication that this showed any kind of convincing result. If it was my product, I’d really want to demonstrate that the thing worked. Not that it seems to matter, evidently, since the campaign is already way over-funded.

•There is a vagueness about the whole affair that is offputting. As we saw at the outset, the gadget claims to ‘quiet’ snoring – but that’s a very subjective thing. Nowhere do we find any definitive terms about how much it will quiet the snoring. The one piece of solid empirical data comes from the decibel meter in the videop clip, and I can tell you, that’s not showing any ‘quieting’.****

•The ‘team members’ for the campaign include far too many marketing and advertising people for my liking. Because that’s what the whole thing smacks mostly of – marketing.

•There are some uncomfortable legal problems. The Indiegogo campaign for Silent Partner holds a disclaimer that says

“Participation in this campaign is in accordance with the Terms and Conditions listed on the Silent Partner website.”

As of this writing, there are no Terms and Conditions listed on the Silent Partner website. There is a link there, alright, or at least words saying ‘Terms and Conditions’, but clicking on them does nothing. I could not find any such terms elsewhere on the very spare site. I think you can see that this is a legal disaster. People who have contributed to the Indiegogo campaign have agreed to do so under non-existent terms. Or terms that don’t exist yet. The makers of Silent Partner could, at any time, write a contract that simply says “I agree that the product might not work as stated and I understand that I will not get my money back under any circumstances”. And then make the link active.*****

In this legal respect, I also feel that Silent Partner might be wandering into the dubious area of being a medical device. This is a highly-controlled and legally rigid field. I’m sure they will vehemently deny it is such a device, but snoring can be a sign of underlying medical problems, and it’s an issue that you should take up with your doctor if it’s a significant detriment to your sleep [to be fair, the FAQ on the Indiegogo campaign site does indicate that you should consult your doctor if you have sleep apnea, but sleep apnea is only one of quite a few serious snoring-related problems].

To Wrap Up

My professional audio experience and technical knowledge tells me that Silent Partner is quite unlikely to show results in the manner claimed. Indiegogo provides little redress for failed campaigns, and especially for investors getting their money back. This, and the fact that there are no Terms and Conditions listed anywhere on the Indiegogo page or on the Silent Partner official site should make someone think twice before spending their money on this product.

But hey, you did learn a thing or two about noise cancellation and acoustic science, right, so your time here has not been entirely without benefit…


Footnotes:

*It is possible to hear naturally-occurring phase related phenomena. For this to happen, a sound needs to be combined with a copy of itself in such a way that it has some semblance of coherence and phase alignment. The most common manifestation of this is with reverberation or echo. You may have experienced this as a kind of ‘dead’ spot with your tv sound, perhaps; when you sit in a particular spot in the room, the sound seems to be muted and quiet, compared to most other places in the room. This is because the phase-changed reflections off the wall are combining with the actual tv sound to effect a phase-cancellation situation. It will never be as perfect as an electronically contrived version, but it can be quite profound given the right circumstances.

**Car manufacturers in concert with electronics firms like Harman and Siemens – have been playing with ANC for a fair few years now. Because the concern here is mostly with inhibiting road rumble, it’s actually not out of the question that it can work; longer, lower waveforms are less directional for the human ear, and so the necessity for the listener to be in a ‘sweet spot’ is not nearly so critical. Nevertheless, the technical requirements are still complex, and it hasn’t so far caught on in a big way.

***It also uses technical waffle: “subwavelength active noise cancellation” is an entirely meaningless term. Sub what wavelength? The clip with the decibel meter is technical waffle too, which as we’ve seen means precisely nothing.

****An expert audio colleague of mine points out that the sound meter display in the video clip is actually an added visual effect. It’s hard to know what to make of this – the inference is of course that the creators of Silent Partner consciously chose the numbers that are being displayed – numbers that are, as we discussed previously, really only indicative of rather loud normal snoring. We could speculate that this a a kind of ‘cover your ass’ move, inasmuch as they can always point to it and say “This is all we promised it would do…”

*****There are a few non-active links on the site. It opens up the possibility of jiggery-pokery. In the past I’ve seen this problem and commented on it and then, mysteriously, the links work – and the content under them is as outrageous as you expect. I’m not saying the Silent Partner people are doing this, just that it does happen with rather alarming frequency with these kinds of products.