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.


Humz R Us


The hummadruz hit the mainstream news this week with the Guardian science pages asking on Wednesday What is the mysterious ‘global Hum’?

The article features the investigations of science teacher and university lecturer Glen MacPherson, who, among other things, has created the formidable World Hum Map and Database an interactive website where users can register their encounters with the Hum. MacPherson believes that a scant 4% of humans are able to hear the Hum and has carried out numerous investigations as to what it might be.

Probably unsurprisingly for readers of Hummadruz, he can trace it to no single cause, and cites everything from freeway noise, through ventilation systems to blast furnaces as possible candidates. He does not mention fish. Ultimately, he concludes that the Hum is not based in any real world noise generation:

Rather, he argues it involves a neurological element

You will, of course, have already surmised that I am in accordance.

Photo by Francesco Paggiaro from Pexels + Photo by Linus Nylund on Unsplash

Resting on Yer Yannies?


So, you’ve almost certainly encountered the phenomenon doing the rounds that is the Laurel/Yanny meme. For those living on remote mountain tops who only come down from time to time for the internet connection, it goes like this: there is a voice recording of the word ‘Laurel’ that is variously heard by listeners as either Laurel, or, bizarrely, as Yanny. I say bizarrely, not to contradict all those who hear the word as Yanny, but because the word that is being said is actually Laurel, no matter which way you perceive it.

If you haven’t come across it, you can make yourself familiar with its oddness on this YouTube clip from The Guardian:

What did you hear – Laurel, or Yanny? Either way, don’t worry, it appears that the vote is pretty much split 50/50 at time of this writing, with Laurel very slightly ahead. Personally, from the original recording it always sounds like Laurel to me, but others vehemently defend it as Yanny. So what’s going on here?

I think it’s all about frequency response. I was intrigued to hear friends say things like “It sounded like Yanny on my laptop, and then later when I heard it through my Beats, it sounded like Laurel…”  so I decided to do a little experiment. Have a listen to the clip below – preferably through decent speakers or headphones (your laptop or tablet speakers will colour the result), and tell me if you think I’m right. Initially, I thought the computer voice used in the original was playing a significant role, but in this demonstration, I’ve done the same thing with my own voice, and while the treated version sounds to me more like nearly than Yanny, the effect definitely persists on a real voice.*

What I think is going on is that the formants used in the word Laurel have high-frequency overtones that are more apparent in some circumstances than others. The more biased your playback speakers are to the high frequencies, the more likely you’ll hear Yanny. The more low frequency content, the more likely you’ll hear Laurel.

What do you think? Do you hear differences in the above clip? Let me know your thoughts in the comments.

UPDATE: This Wired deconstruction is the best examination around. I completely concur with the technical discussion toward the end, which follows on from my thoughts above.

FURTHER UPDATE: Brainstorm/Green Needle ~ here is a different – and for my money, better – demonstration of a shapeshifting word from Twitter user @maxmoefoe

*I invariably hear the yanny as yearly, and I know this is true for others. The Yanny contingent variously hears yanny, yammy, yearly, yelly, yermy, but the Laurel contingent only ever hears Laurel

Wine Glass Science

[Please note: the original video for this post, which was being relentlessly flogged around Facebook, has been removed – presumably in line with the recent Facebook policy of fact-checking pseudoscience. It has furthermore vanished from anywhere else on the internet, as far as I can determine.

The new video which I’ve now embedded comes courtesy of TEDx and is a good example of why their brand is now widely ridiculed and has little intellectual currency. It was, apparently, a bridge too far even for them, provoking this cautionary warning on YouTube: “Please do not look to this talk for medical advice. We’ve flagged this talk, which was filmed at a TEDx event, because it appears to fall outside TEDx’s content guidelines. Resonant Frequency Therapy has not been proven effective by scientific research. TED”

The main text of my article remains unaltered, and so there may be references to the original clip that don’t make exact sense in the new context. I believe the claims made by in the TEDx talk by Anthony Holland are in line with claims made in the original video.]

This video, featuring a person who is, here, and elsewhere, described variously as ‘Doctor’ and ‘Professor’ Anthony Holland, has been doing the rounds on Facebook recently. It carries the duplicitous suggestion that there exists a way to cure cancer with sound waves. Further, it implies that this remarkable medical discovery is, for some reason, kept from the people who need it most because [insert paranoid fantasy du jour here].

Let’s take a look at what they’re saying here, and at the personage of Dr/Prof Holland and his bona fides.

First of all, let me say right off the top that the breathless claim in the title is entirely true. 100% accurate, in fact. Sound waves can, indeed, destroy cancer cells. Sound can rip those little suckers into protoplasmic shreds like a combine harvester in a daisy field.

But here’s the thing: killing cancer cells is not hard.

If you take a cancer cell culture and pour sulphuric acid on it, those cells will die. And I think you can see why no-one is galumphing around claiming that sulphuric acid is a cure for cancer. The problem for cancer treatment is not destroying cancer cells – we know literally hundreds of ways to do that – the problem is destroying cancer cells without destroying all the other cells in the human being that has cancer. If you can be bothered to watch the video I’ve linked above, you’ll have already seen where the truck-sized loophole in the claims lies:

“While the laboratory results have shown great promise, living subjects have not been studied”

Just a teensy detail that doesn’t stop Anthony Holland from attempting to raise money for his folksy notion, nor parading it on the TEDx stage.

The video also advances a contentious idea that is common among the practitioners of alternative medicine – the belief that all things are imbued with ‘frequencies’*. This is a kind of magical thinking that is as persistent as it is meaningless. If one could only find the ‘frequency’ of pancreatic cancer cells, the video infers, one would hold the key to zeroing in on just those cells and no others.

Unfortunately, a method for doing that kind of zeroing-in with Mr Holland’s amazing sound rays is not forthcoming in the video… nor indeed, anywhere else you might care to look. This is hardly surprising, because it’s not science, and Mr Holland is not a scientist. He’s also not a doctor, as far as I can tell, and certainly not a doctor of medicine, nor of any other discipline that might give him expertise in the field in which he is claiming these incredible discoveries. He is a professor – well, an associate professor, anyway – of music.

It is possible that sound might have some unique applications in medicine, and there are a number of possibilities entering the medical literature. For example, a technique called Ultrasound-Mediated Microbubble Destruction (UMMD) has been advanced as a method for weakening cancer cell walls in order to facilitate drug-uptake.

These innovations come from accredited medical specialists, however, and are based on well-researched science, quite unlike Anthony Holland’s colourful ‘smash it like a resonating wineglass‘ magic trick.

*Go on, think about it for a few minutes. Can a cell have a frequency? What about a clump of cells – say, in the form of a zucchini. Is there a zucchini frequency? Does water have a frequency? Most of a cancer cell is water. Is water the same frequency as a cancer cell? A zucchini is mostly water – are cancer cells and zucchinis the same frequency? It’s nonsense of the most simplistic kind.

This idea of frequencies is as vague and meaningless as the associated notion of ‘energy’, another ubiquitous staple of pseudoscience.

Sonic Assassins


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.

The Sound of Silence


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.


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


“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.



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.



“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.