Hearing and Language

Your ears emit sounds

There’s a fascinating article on the evolution of hearing in The Scientist that also contains an interesting gem – your ears produce sounds as well as perceiving them.

In addition to amplifying hair-cell activity, these active mechanisms manifest as spontaneous movements of the hearing organ, oscillating even in the absence of sound stimuli. Such spontaneous movements actually produce sound that is emitted through the middle ear to the outside world and can be measured in the ear canal.

I wondered whether this only applied to non-human animals – it’s not clear from the text – but a brief search brings up various studies on spontaneous otoacoustic emissions in humans. For example:

Spontaneous otoacoustic emissions were evaluated in 36 female and 40 male subjects. In agreement with the results of previous surveys, emissions were found to be more prevalent in female subjects and there was a tendency for the male subjects to have fewer emissions in their left ears.

It also turns out that spontaneous otoacoustic emissions are used to test hearing in newborn babies.

It’s an interesting problem, because normally hearing is tested by giving people tests where they are played various sounds or silence at certain time points and they have to signal whether they think they heard the sound, and correct decisions are counted.

This clearly doesn’t work with babies but one way of testing hearing is by measuring the response of nerve signals that connect to the auditory brain stem.

This training video shows how it’s done but in the last section there’s a test which relies directly on detecting the ‘echoes’ created by otoacoustic emission when a tone is played directly into the ear.

Link to The Scientist article on the evolution of hearing.

Hearing WiFi

New Scientist has a fascinating article on Frank Swain who has hacked his hearing aid to allow him to hear WiFi.

It’s a great idea and riffs on various attempts to ‘extend’ perception into the realm of being able to sense the usually unnoticed electromagnetic environment.

I am walking through my north London neighbourhood on an unseasonably warm day in late autumn. I can hear birds tweeting in the trees, traffic prowling the back roads, children playing in gardens and Wi-Fi leaching from their homes. Against the familiar sounds of suburban life, it is somehow incongruous and appropriate at the same time.

As I approach Turnpike Lane tube station and descend to the underground platform, I catch the now familiar gurgle of the public Wi-Fi hub, as well as the staff network beside it. On board the train, these sounds fade into silence as we burrow into the tunnels leading to central London.

I have been able to hear these fields since last week. This wasn’t the result of a sudden mutation or years of transcendental meditation, but an upgrade to my hearing aids. With a grant from Nesta, the UK innovation charity, sound artist Daniel Jones and I built Phantom Terrains, an experimental tool for making Wi-Fi fields audible.

Do also check out a fantastic radio documentary by Swain we featured earlier this year which is a brilliant auditory journey into the physics and hacking of hearing and hearing loss.

Link to NewSci article ‘From under-hearing to ultra-hearing’

From under-hearing to ultra-hearing

The BBC World Service has a fascinating radio programme on hearing loss and how it’s spurring the move towards auditory enhancement technology for everybody.

The documentary, called Hack My Hearing, was created by science writer Frank Swain who is suffering hearing loss. He explores different forms of hearing disturbance and looks at technologies that aim to enhance hearing and how they soon might provide ‘super human’ auditory abilities.

One of the best things about the documentary is that it has been brilliantly engineered so you can experience what most of the forms of hearing loss and hearing enhancement in the documentary sound like.

It is definitely one to be listened to on headphones and it sounds wonderful.

Sadly, it’s only available as streamed audio at the moment, but you can listen to the full programme at the link below.

Update: The programme is now also available from the BBC as a podcast – downloadable directly as an mp3.

Link to Hack My Hearing streamed audio.

Listening for the voices of the dead

I’ve got an article in The Observer about our tendency to perceive meaning where there is none and how this inadvertently popped up in one of the strangest episodes in the history of psychology.

The article discuss the work of psychologist Konstantīns Raudive who began to believe that he could hear the voices of the dead amid the hiss of radio static – after, it must be said, much re-recording and amplification of the samples.

He wrote a 1971 book called Breakthrough where he explained his technique which was even accompanied by a flexidisc that has lots of not very convincing examples of the dead speaking through noise. You can listen to it on YouTube if you’re so inclined.

He gained widespread media attention but subsequent scientific studies found that everyone was hearing something different amid the static, making it one of the most well-know examples of illusory meaning or pareidolia of its time.

However, the experience of illusory meaning has become widely studied for its relationship to magical thinking and hallucination but was even recently deployed as a practical tool for the assessment of dementia.

More in the full article at the link below. It’s been given a somewhat odd title but hopefully, it should be fairly self-explanatory.

Link to Observer article on illusory meaning.

With every language, a personality?

The Medieval Emperor Charlemagne famously said that “to have another language is to possess a second soul” but the idea that we express different personality traits when we speak another language has usually been left as anecdote.

But The Economist takes this a step further and examines the science behind this idea – which may have more weight than we might first think.

It looks at the issue from lots of intriguing angles. Perhaps the most obvious is that bilingual speakers may have different associations with each language – for example, home and work – and so come to associate different sorts of social behaviours with each.

One of the most interesting is how different language structures might allow for different behaviours, although a grammatical explanation for why the Greeks having a tendency to interrupt during conversation is given short shrift

Is there something intrinsic to the Greek language that encourages Greeks to interrupt?…

In this case, Ms Chalari, a scholar, at least proposed a specific and plausible line of causation from grammar to personality: in Greek, the verb comes first, and it carries a lot of information, hence easy interrupting. The problem is that many unrelated languages all around the world put the verb at the beginning of sentences. Many languages all around the world are heavily inflected, encoding lots of information in verbs. It would be a striking finding if all of these unrelated languages had speakers more prone to interrupting each other. Welsh, for example, is also both verb-first and about as heavily inflected as Greek, but the Welsh are not known as pushy conversationalists.

There’s plenty more interesting analysis in the Economist article and it turns out the magazine’s language blog, called Johnson (relax Americans, it’s a reference to Samuel Johnson) is very good as a whole.

Link to ‘Do different languages confer different personalities?’

The deafening silence

All silences are not equal, some seem quieter than others. Why? It’s all to do with the way our brains adapt to the world around us, as Tom Stafford explains

A “deafening silence” is a striking absence of noise, so profound that it seems to have its own quality. Objectively it is impossible for one silence to be any different from another. But the way we use the phrase hints at a psychological truth.

The secret to a deafening silence is the period of intense noise that comes immediately before it. When this ends, the lack of sound appears quieter than silence. This sensation, as your mind tries to figure out what your ears are reporting, is what leads us to call a silence deafening.

What is happening here is a result of a process called adaptation. It describes the moving baseline against which new stimuli are judged. The way the brain works is that any constant simulation is tuned out, allowing perception to focus on changes against this background, rather than absolute levels of stimulation. Turn your stereo up from four to five and it sounds louder, but as your memory of making the change rapidly fades, your mind adjusts and volume five becomes the new normal.

Adaptation doesn’t just happen for hearing. The brain networks that process all other forms of sensory information also pull the same trick. Why can’t you see the stars during the daytime? They are still there, right? You can’t see them because your visual system has adapted to the light levels from the sun, making the tiny variation in light that a star makes against the background of deep space invisible. Only after dark does your visual system adapt to a baseline at which the light difference created by a star is meaningful.

Just as adaption applies across different senses, so too does the after-effect, the phenomenon that follows it. Once the constant stimulation your brain has adapted to stops, there is a short period when new stimuli appear distorted in the opposite way from the stimulus you’ve just been experiencing. A favourite example is the waterfall illusion. If you stare at a waterfall (here’s one) for half a minute and then look away, stationary objects will appear to flow upwards. You can even pause a video and experience the illusion of the waterfall going into reverse.

It’s a phenomenon called the motion after effect. You can get them for colour perception or for just lightness-darkness (which is why you sometimes see dark spots after you’ve looked at the sun or a camera flash).

After-effects also apply to hearing, which explains why a truly deafening silence comes immediately after the brain has become adapted to a high baseline of noise. We perceive this lack of sound as quieter than other silences for the same reason that the waterfall appears to suck itself upwards.

So while it is true that all silences are physically the same, perhaps Spinal Tap lead guitarist Nigel Tufnel was onto something with his amplifier dials that go up to 11. When it comes to the way we perceive volume, it is sometimes possible to drop below zero.

This was my BBC Future from last weekend. The original is here.

The Mystery of The Cuckoo’s Calling

One of the computational linguists who applied forensic text analysis to JK Rowling’s books to uncover her as the author of The Cuckoo’s Calling describes the science behind his investigation in a post for Language Log.

It seems Rowling’s authorship was originally leaked by her law firm and a UK newspaper turned to two academics who specialise forensic text analysis to back up their suspicions.

On of those academics, computer scientist Patrick Juola, wrote a piece for Language Log to describe how this sort of text analysis works.

Of the 11 sections of Cuckoo, six were closest (in distribution of word lengths) to Rowling, five to James. No one else got a mention.

Another feature I used were the 100 most common words. What percentage of the document were “the,” what were “of,” and so on. Again, a rich data set that is easy to extract by computer. Using an otherwise similar analysis (including cosine distance again), four of the sections were Rowling-like, four were McDermid-like, and the other three split between James and Rendell.

I ran two tests based on authorial vocabulary. The first was on the distribution of character 4-grams, groups of four adjacent characters. These could be words, parts of words (like four letters “nsid” that would be inside the word “inside”) or even parts of two words (like the four letters “n th” as part of the phrase “in the”)… I also ran on word bigrams, pairs of adjacent words, again a feature with a good track record.

The character 4-grams showed a preference for McDermid, with 8 sections close to her. Three were Rowling-like, and no one else was mentioned. The word pairs, on the other hand, were clearly Rowling-like (9 sections, against 2 by McDermid, no one else mentioned).

If you want to play around with some of the technology behind both Juola’s authorship attribution work, or that of Peter Millican – the other academic contacted by the press to do an analysis – you can actually download them both from the net.

Juola’s JGAAP programme is available here while you can get Millican’s at this page.

Rumours that Mind Hacks is actually written by Natalie Portman will be strictly denied.

Link to Juola’s post on Language Log.

A world of swearing

The Boston Globe has a short but fascinating interview on the history of swearing where author Melissa Mohr describes how the meaning of the act of swearing has changed over time.

IDEAS: Are there other old curses that 21st-century people would be surprised to hear about?

MOHR: Because [bad words] were mostly religious in the Middle Ages, any part of God’s body you could curse with. God’s bones, nails, wounds, precious heart, passion, God’s death—that was supposedly one of Queen Elizabeth I’s favorite oaths.

IDEAS: Have religious curses like that lost their power as the culture becomes increasingly secular?

MOHR: We still use them a lot, but we just don’t think of them as bad words. They’re very mild. If you look at lists of the top 25 swear words, I think “Jesus Christ” often makes it in at number 23 or something….The top bad words slots are all occupied by the racial slurs or obscene—sexually or excrementally—words…

IDEAS: Are blasphemy, sexuality, and excrement the main themes all over the world?

MOHR: As far as I know, they’re mostly the same with a little bit of regional variation. In Arab and Spanish-speaking Catholic countries, there’s a lot of stuff about mothers and sisters. But it’s pretty much the same.

Interesting, there is good evidence that swear words are handled differently by the brain than non-swear words.

In global aphasia, a form of almost total language impairment normally caused by brain damage to the left hemisphere, affected people can still usually swear despite being unable to say any other words.

Author Melissa Mohr has just written a book called Holy Sh*t: A Brief History of Swearing which presumably has plenty more for swearing fans.

Link to Boston Globe interview (via @leraboroditsky)
Link to details of Holy Sh*t: A Brief History of Swearing.

The uncertain dance of the spoken word

Stanford Magazine has a wonderful article by a writer who relies on lip-reading and experiences speech through this subtle movement-based language.

Rachel Kolb skilfully describes how this works, and more importantly, feels.

The part where she describes how she experiences accents is just amazing:

Accents are a visible tang on people’s lips. Witnessing someone with an accent is like taking a sip of clear water only to find it tainted with something else. I startle and leap to attention. As I explore the strange taste, my brain puzzles itself trying to pinpoint exactly what it is and how I should respond. I dive into the unfamiliar contortions of the lips, trying to push my way to some intelligible meaning. Accented words pull against the gravity of my experience; like slime-glossed fish, they wriggle and leap out of my hands. Staring down at my fingers’ muddy residue, my only choice is to shrug and cast out my line again.

The full article is highly recommended. Both fascinating and wonderfully written.

Link to ‘Seeing at the Speed of Sound’ (via and thanks to @stevesilberman)

Deaf police to monitor security cameras in Mexico

Deaf police officers have been recruited to monitor security cameras in the Mexican city of Oaxaca because of their ‘heightened visual abilities’.

There’s a brief and somewhat clunky English-language news article from the local paper that describes the project:

Ignacio Villalobos Carranza, Deputy Secretary for the Ministry of Public Security of Oaxaca, said most of the monitoring of the 230 cameras is done by law enforcement officials that are hearing or speech impaired. He noted these police officers have a very strong deaf and visual sense and can better detect what is happening in different places where the cameras are located; they can often remotely read the conversations of people, to the benefit of this security system that operates 24 hours a day.

The ability to lip read conversations is a fantastic advantage, but the project raises the question of whether deaf people would actually be better at security monitoring in general.

As far as I know, there are no studies comparing hearing and deaf people on specific monitoring tasks but there is evidence that deaf people have certain advantages in visual attention.

This isn’t vision in general, such as having sharper visual acuity – where there seems to be no difference, but there is good evidence that deaf people are better at noticing things in the periphery of vision and detecting movement.

This potentially makes them perfect for the job and likely better than their hearing colleagues.

So the project turns out to be a targeted way not of recruiting ‘disabled people’ into the workforce, but of recruiting the ‘super able’. In fact, turning the whole idea of disability on its head.

There’s also a Spanish-language video report from BBC Mundo if you want more información.

Link to brief new article on the project.
Link to Spanish-language video report from BBC Mundo.

An unplanned post-mortem

My latest Beyond Boundaries column for The Psychologist explores the space between he we study suicide and the experience of families affected by it:

Suicide is often considered a silencing, but for many it is only the beginning of the conversation. A common approach to understand those who have ended their own lives is the ‘psychological autopsy’ – a method that seeks to reconstruct the mental state of the deceased individual shortly before the final act. The testimony of friends and family is filtered through standardised assessments and psychiatric diagnoses. The narrative is ‘stripped down’ to the essential facts. A life is reduced to risk factors.

Psychologists Christabel Owens and Helen Lambert were struck by the contrast between the goal of the professionals in the interviews and how the friends and family of the deceased used the opportunity to tell their story and to make sense of their loss. ‘The flow of narrative’, they note in their recent study, ‘can often be unstoppable’. The researchers returned to the transcripts of a 2003 psychological autopsy study, but instead of using the interview to construct variables, they looked at how the friends and families portrayed their lost companion.

As suicide is both stigmatised and stigmatising the personal accounts often contained portrayals of events that presupposed possible moral conclusions about the deceased. For example, by tradition, those who have cancer are discussed as heroic fighters, facing down death with courage and resolution. The default stories about people who commit suicide are not nearly so generous, however, and to navigate this treacherous moral territory bereaved friends and family often called on other, more acceptable, social stereotypes to make sense of the situation.

The suicides of women were largely portrayed in medical terms, as being so weakened by negative experiences that they were unable to prevent a decline into mental illness. The suicides of men, on the other hand, were barely ever described in terms of mental disorder. Male suicide was typically described either as the end result of having ‘gone of the rails’, a self-directed descent into antisocial behaviour, or as a ‘heroic’ action, demonstrating a final defiant act against an unjust world.

Deaths were filtered through gender stereotypes of agency and accountability, perhaps to make them more acceptable to an unkind world. Owens and Lambert’s study highlights the stark contrast between how researchers and family members interpret the same tragic events. As professionals, we often do surprisingly little to mesh together the bounded worlds of science and subjectivity, but the study demonstrates the power of the personal narrative. It affects us even after death.

Thanks to Jon Sutton, editor of The Psychologist who has kindly agreed for me to publish my column on Mind Hacks as long as I include the following text:

“The Psychologist is sent free to all members of the British Psychological Society (you can join here), or you can subscribe as a non-member by going here.

Link to original behind pay wall.

BBC Future column: earworms

From a couple of weeks ago, my column from BBC Future, about everyday brain quirks (as I’ve mentioned previously). Thanks to Maria Panagiotidi for help with this one.

“Earworms”, some people call them. Songs that get stuck in your head and go round and round, sometimes for days, sometimes for months. For no apparent reason you cannot help yourself from humming or singing a tune by Lady Gaga or Coldplay, or horror upon horrors, the latest American Idol reject.

To a psychologist – or at least to this psychologist – the most interesting thing about earworms is that they show a part of our mind that is clearly outside of our control. Earworms arrive without permission and refuse to leave when we tell them to. They are parasites, living in a part of our minds that rehearses sounds.

We all get these musical memories, and people appear to have different ones, according to a team at Goldsmiths University in London, who collected a database of over 5,000 earworms. True, the songs that we get stuck with tend to be simple and repetitive, but it seems we are not all singing the same number one song at the same time.

Lost in music

Neurologist Oliver Sacks wrote in his book Musicophilia that earworms are a clear sign of “the overwhelming, and at times, helpless, sensitivity of our brains to music”. Music is defined by repetition, just like earworms, and this might make earworms so hard to shake – they are musical memories that loop, say a particular verse or a hook, forever repeating rather than running to completion. Some people report that singing an earworm to the end can help get rid of it (others report in frustration that this does not work at all).

As well as containing repetition, music is also unusual among the things we regularly encounter for being so similar each time we hear it. Fences are visually repetitive, for example, but each time you see the same fence you will look at it from a different angle, or in different light. Put a song on your stereo and the sound comes out virtually identical each time. Remembering is powerfully affected by repetition, so maybe the similarity of music engraves deep grooves in our mind. Grooves in which earworms can thrive.

Another fact about earworms is that they often seem to have something interesting or usual about them. Although they will often be simple and repetitive bits of music, tunes that become earworms have a little twist or peculiarity, something that makes them “catchy”, and perhaps this is a clue as to why they can take hold in our memory system. If there was nothing unique about them they would be swamped by all the other memories that sound similar too.

Slave to the rhythm

If you have got a particularly persistent earworm you can suffer an attack of it merely by someone mentioning the tune, without having to hear it. This proves that earworms are a phenomenon of long-term memory, rather than merely being a temporary “after-image” in sound.

But this is not the whole story. Human memory researchers have identified so called “slave systems” in our short-term memory, components of the mind which capture sights and sounds, keeping them alive for a short time while we focus on them.

One slave system is the “mind’s eye”, capturing visual information, another is the “inner ear”, the part we use for remembering phone numbers, for instance. It is this second part that seems to get infected with earworms. Rather than rehearse our plans for the day, idle thoughts, or lists of things to remember, the inner ear gets stuck on a few short bars of music or a couple of phrases from a song. A part of us that we normally do not have to think about, that should just do what we ask, has been turned against us, tormenting us with a jukebox request that we never asked for.

That our minds are not a unity is one of the basic insights of modern psychology – it is the story Dr Freud was telling, and, although it differs on many of the details, modern cognitive neuroscience says a similar thing. The sense of our selves is not the only thing going on in our minds, psychology says. The mind is an inner world which we do not have complete knowledge of, or have control over.

Mind games

Fortunately psychology can provide some vital intelligence on how to deal with an unruly mind. Consider the famous “don’t think of a white bear” problem, which as it implies involves trying not to think about white bears. Try this yourself, or you can set it as a challenge for a loved one you would like to torment. This problem is a paradox: by trying not to think of a thing you constantly have to be checking if you are still thinking of it – re-invoking precisely the thing you are trying not to think of.

The general solution for the white bear problem is to do something else, to avoid both thinking of the white bear and not thinking of the white bear. For earworms, the solution may be the same. Our inner ear, a vital part of our cognitive machinery for remembering and rehearsing sounds, has become infected with an earworm. This is a part of ourselves which is not under our control, so just sending in instructions to “shut up” is unlikely to be of much help (and has been shown to make it worse). Much better is to employ the inner ear in another task, preferably something incompatible with rehearsing the earworm.

If earworms survive because of their peculiarity, the hook that makes them catch, then my prediction for ridding yourself of an earworm is to sing songs that are similar. If your mind is poisoned by Brittany Spears’ Toxic, for instance, then try singing Kylie Minogue’s appropriately titled Can’t Get You Out Of My Head. By my theory this will erode the uniqueness of the memory habitat that lets the earworm survive. Let me know if it works!

Link: My columns at BBC Future
Link: UK readers – you’ll have to try it via here

Sound trip

A fascinating excerpt about a hallucinogenic drug called DiPT that only causes hearing distortions – from p310 of the book Hallucinations: Research and Practice:

A member of the tryptamine chemical family, diisopropyltryptamine (DiPT) is a fascinating substance because, unlike most hallucinogens, its effect are predominantly auditory. It is also probably less sensitive than other hallucinogens to the mindset of the user, the setting in which it is ingested, and other psychological considerations, perhaps because the auditory system has become less salient to the human organism as we have evolved into a vision based species.

In general, auditory pitch is perceived as lower than normal, and harmonious sounds lose their resonance with one another. This dissonance is even perceived by people with perfect pitch, which has some implications about where in the processing stream DiPT’s effects occur. Voices are also altered and disharmonious with each other.

DiPT has a few other known effects; it would seem to call for further investigation from those interested in the neurology of sound, music and verbal language processing. For example, it would be fascinating to know the effects of this substance on perceptions of tonal languages such as Chinese, Huichol, or Dogon; would it alter the words perceived as being spoken?

Link to book details.

Buried words

I’ve just found a fantastic video that explains the speech-impairing disorder aphasia to children of all ages.

Its called ‘The Treasure Hunt’ and was created by speech pathologist Shiree Heath and it went on to win first place in the Society for Neuroscience’s video competition.

The video combines a cartoon treasure hunt with recordings of a real-life aphasia patient who seems to be affected by a type of anomic aphasia where affected people have trouble with saying names of objects or items.

It’s worth noting that this is only one of many types of speech-affecting aphasias that are possible after brain damage, although this is perhaps the one that has been most delightfully described so far.

Link to The Treasure Hunt video (via @mocost)

Mixing up a decade of All in the Mind

The amazing ABC Radio National programme All in the Mind is ten years old and is celebrating by mixing up some specially themed editions from its extensive archives.

First up is the psychology and neuroscience of sex that tackles everything from gender myths to the neuroscience of female orgasm.

The following edition, to hit the wires next week, is a special on consciousness and there’s plenty more gold on its way.

All in the Mind is one of the few programmes that is as interesting to professionals as it is to enthusiasts and if you’ve never had a listen, now’s a good chance to check out some of the audio.

Link to All in the Mind site.
Link to 10th Anniversary Special 1: Getting Sexy.

I am yours for 2 coppers

I’ve just found a wonderful 1973 study on the psychoanalysis of graffiti that discusses how unconscious desires might be expressed through public scrawlings.

It has a completely charming table that compares graffiti from A.D. 79 Pompeii with 1960’s Los Angeles to demonstrate the similarity of themes across the centuries.

The author concludes that “aggressive-destructive and incorporative wishes are similarly satisfied by the wall writer at the expense of the wall owner” although overtly sexual images should be considered as definitely expressing sexual themes.

Link to locked 1973 study the psychoanalysis of graffiti.