Turning It Up To 11?

screech2So WIRED is currently running a story with the alarming all-caps headline HACKERS CAN TURN EVERYDAY SPEAKERS INTO ACOUSTIC CYBERWEAPONS – which puts it only a few exclamation marks short of the kind of full conspiracy-theory click-bait trash-dump you’d usually find on Infowars or Above Top Secret (not linking these because, you know, reasons). You’d be forgiven for thinking that the end is nigh in the form of an aural evisceration comparable only to the head-exploding scene in David Cronenberg’s Scanners. WIRED’s headline was one of the tamest for this story as it happens. The India Times pitched it as This next-gen ‘weapon’ is sitting in your room and you don’t even know (at least they eschewed the caps); Channel News ran with RESEARCHERS WARN OF HACKERS WEAPONISING SPEAKERS; and TechRadar breathlessly proclaimed that Your smart speaker could be transformed into an acoustic cyber-weapon by hackers. There were dozens more. Without exception, they all invoke a sense of cataclysmic acoustic terrorism that is extremely worrying.

So, what’s the story? Are we all in danger of suddenly and unexpectedly having our ears literally pierced with cybernetically honed shards of ultrasound, or our bowels emptied with undulating pulses of infrasound? Not so much. The gist of the story is that Matt Wixey, a researcher at a UK technology consultancy firm, made a presentation a few days ago at the hacking conference Defcon in which he demonstrated some software exploits that were capable of causing a variety of speakers to do things for which they weren’t designed.

“…the upshot of it is that the minority of the devices we tested could in theory be attacked and repurposed as acoustic weapons.”

The words to be noticing there are ‘minority‘ and ‘in theory’, because, as we shall see, the more we examine the language used in this article, the further we get away from the apocalyptic headlines that are blazing across the internet.

The first claim to which we might take exception is in the very first paragraph:

“researchers have long known that commercial speakers are also physically able to emit frequencies outside of audible range for humans”

‘Long known’? Really? Well, this does come as news to me, but I suppose it’s possible. Let’s check the citation… Oh guess what? There isn’t one. This is a common problem with pop science articles; a baseless claim, with not a whiff of any supporting reference, is used as the lynch-pin of a spurious argument. I spent ten minutes or so trying to dig up information on this ‘long known’ research and came up with nothing. Perhaps it’s long known, but if so, it certainly isn’t well-known. YMMV, but I think this falls into the category of ‘I’m sure I read it somewhere…’

Let’s deconstruct it anyway. The term ‘commercial speakers’ is misleading and broad. We could put everything from personal ear pieces, through laptop & phone speakers, to tv speakers, car speakers, PA systems, high-end hifi and a host of other things under that floppy metric. Is it reasonable to suggest that all those units could ‘emit frequencies outside of audible range for humans‘? Well, that’s compounding the vagueness by introducing another floppy metric. Most commercial-use audio speakers are, by convention, rated at a frequency response of 20Hz-20kHz. These frequencies represent the very extremes of the aural spectrum that humans can detect at the peak of their hearing capabilities, which, for most people, is around the age of 20. As you pass that age, your hearing goes into decline. If you’re in your mid twenties or later, then literally all commercial speakers are already reproducing frequencies outside your range of hearing. So a claim like that is completely specious in a fundamental way.  Here are some graphs showing typical hearing loss in humans due to the ageing process. The top ends of these graphs (like most audiograms) don’t even bother to go as high as 20kHz, because few people can hear frequencies anywhere near that even under optimal conditions. For typical human hearing, you can plainly see that by about age 35, hearing in both men and women is attenuating significantly in the higher frequencies. No-one at age 35 is hearing all the frequencies reproduced by a good speaker.


For the purposes of argument, though, let’s just assume you’re 19 again and have perfect technical human hearing of 20Hz-20kHz; is it possible that ‘commercial speakers’ are capable of reproducing frequencies higher or lower than that? Well, the answer is: some, maybe, a bit. What you need to know is that, for the most part, the electronics of most amplification systems that drive speakers clamp (or bandwidth-limit) the frequency outputs to that range. Why? Because it’s simply energy-inefficient to reproduce frequencies that are outside the conventional speaker specifications. You’d be wasting power that could be better used elsewhere, or not at all.

Certain kinds of small speakers (like earbuds and computer speakers) might conceivably be capable of reproducing frequencies higher than 20kHz – it’s certainly technically possible. These frequencies are known by convention as ultrasound and it’s feasible that sloppy circuit design might allow such frequencies to pass from the amplification electronics to the speaker, or that a hacker might be able to trick the electronics into generating those kinds of frequencies. Even if this could happen, though, the pertinent question in respect of the ‘acoustic cyber weapons’ of our headline is whether or not it might be of any concern. We’ll look at that in a bit.

So far, I’ve been talking for the most part about high frequencies, but what about the lower part of the range of human hearing – frequencies lower than 20Hz? These are designated as infrasound, and in cyber-weapon banter, are the realm of the infamous Brown Note. Could ‘commercial speakers’ generate anything that could be considered infrasound? Again, some, maybe, a bit. Should you be worried? Short answer – no, but again, we’ll look at exactly why in few moments.

Let’s go back to the WIRED article. Wixey tested a variety of speakers ‘including a laptop, a smartphone, a Bluetooth speaker, a small speaker, a pair of over-ear headphones, a vehicle-mounted public address system, a vibration speaker, and a parametric speaker’, and found that:

…the smart speaker, the headphones, and the parametric speaker were capable of emitting high frequencies that exceeded the average recommended by several academic guidelines. The Bluetooth speaker, the noise-canceling headphones, and the smart speaker again were able to emit low frequencies that exceeded the average recommendations.

There’s a little bit of disingenuousness here. The language is imprecise and obfuscatory. The frequencies ‘exceeded the average’? That’s hardly surprising – an average is an average. You would expect some frequencies to exceed the average! And which academic guidelines? For what, exactly? Smart speakers, headphones, parametric speakers and noise-cancelling headphones are very different beasts, with very different capabilities and very different modes of sonic delivery. Are we talking about some blurry and generic ‘average’ of all possible speakers? Or an ‘average’ of certain selected speakers? Or ‘average’ hearing safety levels (and if so, under what circumstances)? It’s impossible to know, and as becomes obvious by this point in the article, we’re not going to get any cited papers or sources to clarify these extremely diffuse terms.

But again, let’s just give Mr Wixey the benefit of the doubt and speculate that – rather than his tests demonstrating that he was able to exceed the average specs of generic and unidentified speakers and/or listening conditions – he was able to hack the systems to have the units generate frequencies that exceeded the maximum agreed safe levels for human hearing. Should that be of any concern to us as consumers going about our daily lives? Is the Acoustipocalypse predicted by the headlines really upon us?

Not so much. It’s all about power.

Let’s consider the question: “If I wanted to make a sonic weapon, could I?” The Wikipedia entry for Sonic Weapons gives a précis of the landscape that’s pretty representative of anything you’ll find via a search on the rest of the net; it contains a lot of speculation, but not much content. The territory of possibilities that the entry offers covers things like high frequency sound used to deter teenagers from loitering around shopping centres, to long-range acoustic hailing devices used (in one single instance given) to deter pirates. There’s some conjuring up of infrasound as an explanation for a ‘haunted’ laboratory1 and an assertion that ‘High-amplitude sound of a specific pattern at a frequency close to the sensitivity peak of human hearing (2–3 kHz) [sic]2 is used as a burglar deterrent.’ 

And really, those things make up the bulk of the entry, and read like they’ve been written by someone desperately trying to make a case. Nothing there comes under the definition of ‘weapons’ in my opinion. Deterrents, perhaps. Weapons, no.

There’s a smattering of examples of things that could be considered actual weaponry, and they are all devices that generate ‘Extremely high-power sound waves [that] can disrupt or destroy the eardrums of a target and cause severe pain or disorientation.’ That is, devices that make exceptionally loud (and usually highly-focussed) noises – because that’s what they’re designed to do. There are no examples given of actual real world weapons that use infrasound or ultrasound.3

So yes, I could make a sonic weapon, but it would require significant amounts of power, and I wouldn’t bother with frequencies outside those of normal human hearing. I certainly wouldn’t consider using a smart speaker as my starting point.

The idea that power is an important factor in this story is actually hinted at in the WIRED recounting of Matt Wixey’s presentation, if you know what to look for. At one point in the article we learn that:

…attacking the smart speaker in particular generated enough heat to start melting its internal components after four or five minutes, permanently damaging the device

What you’re meant to infer here is, of course, that the infrasound/ultrasound audio energy is so impressively terrifying that it has melted the very speaker itself. No-one actually says that, however, and I strongly suspect that there’s something else at play here, which involves Mr Wixey and his hacking team attempting to get enough power out of the amplification electronics (probably in an effort to generate some impressive decibel figures to bolster their argument), that they overheated the circuitry. People who have spent enough time in the audio business are keenly familiar with this situation – if you run an amplifier too hard, you overheat its electronics. I’ll be the first to agree that a hacker shouldn’t be able to do this kind of thing, but that’s a different kind of problem entirely to making the speaker into a ‘cyber weapon’.

It’s revealed further into the WIRED piece that  Wixey & co didn’t/couldn’t perform any of their hacks remotely:

Wixey wrote simple code scripts or slightly more complete malware to run on each device. An attacker would still need physical or remote device access to spread and implant the malware.

You see how the image of intimidating cyber weaponry hacktivism promoted by the screaming headlines becomes less and less impressive as the article proceeds?

The most charitable take we could give on this story after throwing some rational appraisal at it, is that hackers might, in some cases (like when they’re actually in the same room), be able alter some speakers and cause them to do unpredictable things, such as making unexpected or loud noises or perhaps failing completely. It might also be possible for them to generate some high or low frequencies outside the recommended speaker specs, that could be of concern if it was first established that: such frequencies have deleterious effects on humans, that such an effect could be usefully controlled and that there was sufficient available power in any particular device to cause such frequencies to be strong enough to be dangerous and thus constitute a ‘weapon’. The WIRED article does not lead us to believe that Matt Wixey demonstrated such a scenario to be plausible.4

I’d be prepared to wager that the best that a hacker could currently do with this kind of exploit is to attract the attention of your dog or your pet elephant.5

To be fair, causing speakers to make sudden loud noises could certainly be startling, disorienting, or, in the case of earbuds that are placed in your ear canal (right next to your eardrums), even cause pain or hearing damage. As far as smart speakers or your computer speakers are concerned, though, it’s literally impossible for them to make a noise that is louder than the maximum level that the inbuilt amplifier can create – which is not really that loud, all things considered, and nothing that couldn’t be fixed by killing the power or shoving your device under a mattress. In any case, for this kind of thing to be considered a hacking cyber weapon, I’d expect to see at least some demonstration of a remote hijacking capability. If the hackers require direct physical access to your speakers in order to alter them, then it’s a bit like suggesting that someone who can tamper with the brakes on your car is turning it into a cyber weapon.

Adding in all the palaver about ultrasound and infrasound is nothing more than the invocation of  the bogey-man to spice up what would otherwise be a vaguely-interesting but ultimately pretty inconsequential Defcon presentation. Because research is scant and equivocal when it comes to the effects of what I’ll call ‘extrasound’ on humans, and because the general public doesn’t really know much about what these things actually are, they have become placeholders for all kinds of misleading speculation and pseudoscience.And seriously, there are enough real-world problems to be concerned about right now without pop-tech outlets like WIRED adding extra dollops of neurosis to the churn.

By all means keep us informed that researchers like Matt Wixey are alerting us to the vulnerabilities of modern tech, but let’s just stop with the hyperbolic End Times panic schtick.

1Personally, if I was concerned about credibility in an article concerning science, I wouldn’t list a ‘paranormal investigator’ as a reference in my Wikipedia entry.

2There’s something hideously wrong with this sentence. What exactly is the ‘sensitivity peak’ of human hearing, with that appended figure of ‘2-3 kHz’? Does the sentence simply mean (as I suspect it does) ‘a loud, high-pitched warbling noise’, and if so, why not just say that? And why say ‘close to’ a range of frequencies? Surely, if there’s a range, you just include your frequencies in that range? It’s such a nonsensical piece of writing, and is plainly something conceived by a marketing department. [After thinking on this for a bit, I realised that this describes exactly the sound that my house alarm makes. The system has some transducers inside the house, as well as sirens on the outside. The aim of the interior transducers is to make a loud, screaming warble for the sole purpose of startling any would-be intruder. I’d estimate the frequency of the sound to range between 1-3kHz. w00t! I have a sonic weapon in my house!]

3The Wikipedia entry asserts that ‘Some sonic weapons are currently in limited use or in research and development by military and police forces…’ and ‘make a focused beam of sound or ultrasound‘, but no actual examples or references are given. Any citations throughout the piece that refer to infrasound or ultrasound are generic definitions, speculations or simply irrelevancies. Any of the devices mentioned in the entry that are actually in practical use (for the purposes of crowd control, for example) merely make very loud sounds within the normal spectrum of human hearing. As the Mythbusters demonstrated some years back, when examining the myth surrounding the ‘Brown Note’, infrasound is highly difficult to control, uses a great deal of power and is almost impossible to make directional. It makes for a very poor weapon.

4The WIRED article does quote Professor Timothy Leighton, a researcher at the University of Southampton, who has a published paper in the The Journal of the Acoustical Society of America on the Effects of very high-frequency sound and ultrasound on humans. Professor Leighton et al completed a small study in 2018 which they claim shows mild indications of adverse effects on humans due to ultrasound exposure, but I think we should be cautious about their conclusions. The experiment involved a small sample group of about 50 people and showed a very slight result that wholly relied on statistical P values (a mode of scientific measurement that has been called into question in recent times) to claim significance. Of more concern, the study contained high levels of subjectivity and there was (as far as I can determine from the online version of the paper) no blinding and no control. Subjective metrics used to gather data were vague and open to interpretation (‘inability to concentrate’ for example). The one objective physiological component of the experiment – a measurement of galvanic skin response – did not support the subjective reports, or the researchers’ conclusion.

In addition, the way that certain parts of the paper are worded, and the unusual manner in which participants in the experiment were chosen, gives the distinct impression that the experimenters are starting from a position of an already-existing belief in the harmful effects of ultrasound.

Overall, it’s a poorly-conceived test, and we’d need to see something with much better protocols. many more participants and a much more persuasive data set to draw valid scientific conclusions.

5Dogs can hear ultrasonic frequencies, and elephants can detect infrasound.

6This is clearly evident if you spend even a little time on the web searching for ultrasound or infrasound weapons. It’s a landscape free from rationality, and rife with conspiracy theory and pseudoscience.



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.

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:


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.*


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…


*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.

One Trick Pono

The ‘big’ news in audio this week is that legendary musician Neil Young has introduced a new music player to the world – the Pono. The word ‘pono’, apparently, is Hawaiian for ‘righteous’. The principal selling point of Pono is, according to Mr Young, that it presents the listener with ‘the best quality audio available’. Here he is pitching the concept (badly) to a fairly underwhelmed David Letterman:

Flea, bassist from the Red Hot Chili Peppers, effusively spruiked the Pono experience to Rolling Stone:

“It’s not like some vague thing that you need dogs’ ears to hear. It’s a drastic difference.”

Rolling Stone reports that Flea discerned this ‘drastic difference’ after hearing Aretha Franklin’s ‘Respect’ played in Mr Young’s car. Now, I suppose Neil Young has a pretty good sound system in his Cadillac, but trust me, a car is not an optimal listening environment for a phone conversation, let alone for judging music quality, so I for one am taking the audio assessment of a bass player from a rock band criticized for the egregious loudness of its recordings with a grain of scoff.

See, the problem with this kind of thing is one of perspective. Even if we accept that Pono will deliver an appreciable difference in fidelity to what is already available – and for the record, I don’t – Neil Young thinks enough people care about that to make his idea a commercial viability. He obviously doesn’t go to cinemas, have teenage daughters, listen to the radio, or pay attention in any way to how the great majority of people consume music. He’s failed comprehensively to understand the reason that compression codecs like mp3 caught on in the first place, and, worst of all, he’s possibly the only person in the world not to have learned a business lesson from the VHS/Betamax format war of the late 1970s (which, in case the point needs to be made, showed that people don’t give a flying fuck about quality when it comes down to it). As much as I admire Neil Young as a musician, I think his business acumen sucks.

Let me put it to you from my personal perspective as a prospective Pono punter: I’m a trained sound professional with a love of music – new and old – and an appreciation for the amount of work that goes into the craft of getting it to my ears. I love good quality sound. Occasionally I buy music for the fidelity of its recording. But mostly, I don’t. Mostly I buy it for its content. I buy it for the songs, or to play while I’m making dinner, or to listen to in my car when I want to be able to ignore the hum of the city. I rarely have the time to sit and just listen to a recording in the relatively superior listening environment of my sound studio. I like to take my music with me, so I have some on my phone, and some on an iPod in my car. I have re-purchased music I already owned so I can do this, and have also digitized my not-insubstantial CD collection. Now – WHY ON EARTH WOULD I BUY A PONO AND ALL MY MUSIC AGAIN? I know that, theoretically, mp3 and AAC are inferior to uncompressed digital (whether that extends to the stratospheric192kHz/24-bit sound that Pono offers is arguable…) but I don’t care. I bet the Pono music won’t be as cheap as the iTunes store, and I bet the Pono won’t interface with my car. And I already carry around music on my phone – why would I want another gadget cluttering my pocket? It’s one of the cool things about the iPhone: I have music, a phone, a diary and a camera with me at all times in one unit. What I’m trying to show you here is the vast hurdle that Neil Young is proposing to leap, on the basis that people care about superior sound quality.

An interesting aspect of the reporting of this story is that the press seems to have picked it up under variations of this leader: “Neil Young Expands Pono Digital-to-Analog Music Service”, which, aside from being an entirely inaccurate appraisal of the way the gadget works, rides on the coattails of the hoary old myth that analog recording is somehow magically ‘superior’ to digital. Analog is different to digital. That is all. You may even prefer the sound of old analog recordings over modern digital ones, but that has, these days, nothing at all to do with tehnical quality. It’s merely fashion. And it’s a fashion that can, in fact, be reproduced adequately – for the great majority of listeners – under existing digital audio codecs. Why, if you really want very high quality audio, it’s already available in iTunes (not quite the 192kHz offered by Pono, but Jesus, people – Aretha Franklin IN A CAR???)

My prediction? One year on from the official launch of Pono and you’ll be buying the things on eBay for 50c. Come back and tell me I was wrong.


Another of the matters that I intend to explore regularly on Hummadruz is the veritable trash mountain of  hifi audio myths. Superstitions and irrational belief systems flourish in places where there is a substantial amount of subjectivity and a stratosphere of opinionated experts – especially where there is considerable profit to be had. High end audio is the perfect place to find plenty of hokum.

It’s hard to know where to start with ‘professional’ hifi. There is so much misinformation and gobbledegook that pretty much wherever you turn there’s some implausible gadget or other for improving your sound, from gold-plated digital connectors, through pens that make CDs ‘clearer’ to (quite unbelievably) expensive wooden knobs for your amplifier. And that’s not even tippy-toeing into the world of serious audio fruitcakes.

Today I’m going to examine the simplest, and perhaps the most exploited of all hifi components: speaker cables. The hyperbole spouted by the vendors of these products is voluminous. Their ‘oxygen free, polarized di-electric, elevated-off-the-floor, cryogenically chilled’ cables will make your muddy cloth-filtered music sound like it’s been triple-washed in Persil! It’ll come out of the speakers at a fidelity beyond studio quality!

What’s going on here? Can some bits of wire really make that much difference? Well, yes and no. First of all there’s an important point to note about speaker cables – they carry a much higher level signal than anywhere else in the audio chain because by the time it gets to them it is amplified. In practical terms, what this means is that your actual modulated raw audio signal is at its most powerful going from your amp to your speakers. Why is that important? Because by this time the electrical signal is bumped up way beyond the noise level of all the other components in the system – most of the stuff that can be done to affect the fidelity of the signal itself has already been done.

That being said, what then becomes significant is the best way to get the electrical signal from out of your amp into your speakers with the least impediment possible, and this essentially comes down to one thing: providing the happiest and least reactive conduit for your excitable electrons to travel along. Now there are some mitigating factors involved: no matter how good your path is there is some wear and tear on how well the electrons fare. They are effected by the quality of the conductor, the distance they have to travel and other electrical phenomena such as capacitance and inductance. But here is the critical point: none of these things are really much of a problem in ten feet of speaker cable. In addition, even if you were able to demonstrate some non-optimal electrical artifacts over such a short distance, it is unclear what effect, if any, these have in relation to audio fidelity.

So. What is the most important factor to consider in getting your electrical signal to your speaker? Just one thing: lots of copper. Copper is a terrific conductor of electricity. It’s very kind to the electrons as they pass though, giving them the easiest path to travel that they could ever want. And when we’re talking about ten feet, all being said, that’s really not that much copper.

I’m now going to give you a tip that will save you hundreds of dollars and make your hifi system sound as good as the very nerdiest of your audio-buff friends: for your speaker connections, forget all about the oxygen free, diode rectified, dipped-in-chocolate, used-only-by angels $400-per-foot Pear cables and instead just use a good quality, large gauge twin-core electrical cable.

That’s it! Use some wire like this and no-one on the planet will be able to tell the difference between it and the most expensive cable you can buy! I found the stuff above for less than $2 a metre and you can do even better than that. Sum total for speaker cable for my studio: $45. And that’s for a full 5.1 sound set up, with 6 speaker sources. I could have spent many hundreds of dollars – thousands, even – if I’d done it with a fancy cable brand.

And, in case you’re still wavering in your point of view, consider this story:

In 2007, James Randi put forward his famous Million Dollar Challenge to the makers of Pear cables, defying them to demonstrate in a double blind test that their product would outperform a cheaper good quality cable of the same length (‘outperform’ in this context is understood to mean that it would reliably and repeatedly be preferred as more accurately representing the audio it carried, as assessed by an experienced listener). Predictably, after first calling the Challenge a hoax, and then resorting to ad hominem attacks against Randi, Pear’s CEO Adam Blake refused to participate. This is an unequivocal admission of flim flam. If your product performs as claimed, you can only come out of the Randi Challenge looking absolutely golden (with the added advantage of $1000,000 cash in your pocket). If you back out, then this surely indicates that you are afraid that the results will not bear out the hyperbole in your marketing. There have been, to date, no double-blind experiments that have demonstrated in any way that a cable that costs you thousands of dollars is any better at rendering audio than a good quality one of under a hundred. Indeed, tests that have been undertaken, like this ad hoc (but reasonably conducted) trial made with audiophile Mike Lavigne as the expert listener, tend to show that expensive cables fare no better than cheaper alternatives (something which Mr Lavigne quite admirably concedes).

Audio buffs like to pontificate ad nauseum about the how much difference the supposed ‘high end’ speaker cables make but to those of us who work in the business they just look like nitwits – we don’t use those kinds of cables! So what these people are claiming is that they can hear better sound in the reproduction of the material than we heard when we made it! That, of course, is an absurdity of the highest order.

I’d like to end with a true story. Many years ago, a hifi aficionado acquaintance of mine invited me around to hear his new system. He had spent many thousands of dollars on components, and waxed lyrically about his new speaker cables, which, he said, had improved the fidelity of his music by an impressive order of magnitude. Knowing about my skepticality of such claims, he swore that even I would notice! He sat me down and pressed play on one of his favourite jazz recordings. Could I perceive a superior sound quality? Was I astonished at the clarity of his sound? Well, not so much – I spent a more than a few minutes coming to grips with the fact that his speakers had been wired out of phase, a much more egregious degradation of the listening experience than even speaker leads made of string would have inflicted. And something that he had not even noticed. After we fixed the connections, he went on to maintain that the cables were responsible for a whole new realm of clarity in his listening experience.

‘But what are you comparing them with?’ I asked.

‘With the old ones,’ he said.

‘But you’ve just set your whole rig up in a new room, and you have new speakers,’ I said. ‘How can you possibly tell?’

‘You’re such a skeptic!’ he cried.

And he was right, I am.

Now I’m not suggesting that all hifi buffs would make such obvious mistakes as these, but the thing is, my friend had invested so much money and faith in his speaker cables that he had little choice but to believe that he was witnessing superior sound reproduction. And I do suggest that this phenomenon has more than a little part to play in influencing the subjective experience of listening to recorded music.