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Jul 312014
 
Are the two red lines the same size?  If you can't believe your eyes, how much harder is it to believe your ears?

Are the two red lines the same size? If you can’t believe your eyes, how much harder is it to believe your ears?

Our sense of hearing is amazing, and also an amazing contradiction.

It is simultaneously super-sensitive, but also flawed.  We can hear amazingly quiet sounds (and also incredibly loud sounds possession billions of times greater sound energy), and we can distinguish one sound or voice from a morass of other sounds and voices.  Life without our sense of hearing would be terrible.

But, as amazing as it is, our hearing is still imperfect and flawed.  We’ll allow you to do some testing of your own hearing in this article so you can understand some of your own hearing abilities (and limitations), and you should keep these in mind when evaluating the purchase of possibly expensive audio gear.

Because hearing is a personal and subjective sensation, and subject to external influences and biases, it is a lamentable fact that there is a tremendous amount of nonsense put forward as fact when it comes to audio ‘quality’ and digital music, and the claims some people make about how something will astonishingly transform your listening experience.

We are not saying that all the people who make these claims are dishonest – although it is hard to avoid concluding that some of them are.  Many of them may be misguided fools, or hopeful optimists, and sadly, some of them truly believe what they advocate.

We are also not saying that there is no such thing as good sound and bad sound.  We enthusiastically support and enjoy good sound quality ourselves.  But we are saying that there’s definitely a case of diminishing returns, and that spending more money doesn’t guarantee you ‘more’ sound.

The problem is that the field of sound and musical appreciation encourages misunderstandings and mistakes.  The mind can definitely play tricks on one in many different ways.  For example, the concept of a placebo effect is well-known in medicine – definitely a case of mind triumphing over matter.  As another example, you probably have seen many optical illusions over time – such as the one at the start of this article, where the two red lines seem to be of different size, but are actually identical (more optical illusions here).

The same susceptibility to being tricked applies with sounds and how we hear/sense them.  After all, no-one else can know what we hear or how we hear it, and it is very hard to describe exactly what we are hearing or how it is different from a very similar sound.  While it is a demonstrable fact that one object might be bigger or heavier than another, how can one ‘prove’ that one audio system is providing a better playback of some recorded music than another?

To make things even more complicated, some changes in sounds can be perceived as being ‘better’ than other changes even if the change in sound actually makes it less true to the original.  Do you like some extra bass in your music?  There’s nothing wrong with that, of course, but you’re now moving away from true and total accuracy in the music you play back.  In other words, some ‘inaccuracies’ can even be a good thing.

Part of a multi-channel mixing desk.  Look at all the controls to change the sound for each channel.

Part of a multi-channel mixing desk. Look at all the controls to change the sound for each channel.

Of course, the inaccuracies start way before your amplifier.  The recording engineers make enormous changes to the sound they are putting onto a recording.

They’ll change the tone, add some echo, probably compress the dynamic range, move sounds around the ‘soundstage’, make some sounds more prominent than others, and generally do whatever else they wish as well to make the recorded sound ‘better’ than the original (at least in their opinion).

Confusingly, some changes which at first seem ‘better’ subsequently might end up being thought of as ‘worse’ – a bit like a food item that becomes a favorite, but then, after eating too much of it too often, becomes something you can’t stand the thought of any more in the future.  Yes, the opposite applies as well.  Some sound characteristics which might at first seem disappointing can sometimes end up becoming your favorite.

As an example of the problems inherent in evaluating sound quality, if your ear hears the exact same sound, but one time slightly louder than the other, you will instinctively feel the louder sound is ‘better’ than the quieter sound.  It isn’t ‘better’, it is simply louder, but our auditory perception generally prefers louder sounds over quieter ones.  This ‘trick’ can often be used against us in a Hi-fi showroom, with the salesman playing the most expensive system slightly louder than the less expensive ones, helping us to feel it has a better sound.

We also have very poor auditory memory.  If we hear a piece of music, then a minute later hear it again with a slight adjustment to the tone controls, we might not be able to remember how the original version sounded well enough to perceive the change in sound in the second version.

Don’t Be Bullied or Influenced Into Believing Something is Better than it Is

And, sadly but surely, we are susceptible to the power of suggestion, either consciously or unconsciously.  If you’re read a series of reviews raving about a $10,000 piece of audio equipment, and castigating the inadequacy of your $100 piece of equipment, when you hear the two side by side, you will almost certainly believe you prefer the more expensive piece, even if you hear no difference at all, and if you do hear a difference, you’ll feel secretly proud of your ability to appreciate high-end audio and you’ll assume the difference you are hearing represents an improvement (in the $10,000 item).

You can’t help yourself when you do this.  Here’s a page that lists about 150 different types of bias that affects how we view and think about things.  Most of these biases shape our perception of things without us even realizing it.

A similar effect attaches itself to wine.  It is difficult to describe and to perceive subtle changes in flavor from one wine to another, and so many people tend to buy wine based on the price and brand name.  They reason that a $200 bottle of famous first growth French wine is likely to be much better than a $20 bottle of wine from a local winery they’ve never heard of before, and they sneer at and automatically reject ‘two buck Chuck’ (Charles Shaw – a famous brand of wine sold for $1.99 a bottle at Trader Joe stores).

This reasoning has consistently been shown to be wrong in double-blind taste testings of wines.  When people – either ‘ordinary’ people or noted wine critics – taste a series of wines without knowing which is which, many times the famous French wines are bested by less well-known wines (particularly from NZ and Australia) that cost a mere fraction of the French wines.  This is one of the ugly secrets of the wine industry that few people seek to expose.

Don’t fall into the same trap with audio equipment, and don’t assume you can trust the well-known expensive brand name product to be better than a less expensive product from an unknown company.  This is particularly true now that the Chinese are starting to offer products that give ‘high end’ audio capabilities, but which are sold at low prices.

Many of these new Chinese devices are astonishing bargains, and it is inappropriate to sneer at them due to their Chinese origins and low prices, particularly because some of the higher end companies are also based in China/Hong Kong/Taiwan/Korea, and even the ‘American’ companies probably have their equipment made in China – possibly by the same factories that also now sell their own products under their own brand.

For example, the very high-priced Astell & Kern portable music players (their top of the line AK240 sells for $2500, and some might find it indistinguishable in terms of sound quality from an iPod costing one tenth that much) are actually a subsidiary of the iRiver company, a South Korean company best known for middle of the road portable music players.

More to the point, do you think anyone would hear the difference between the AK240 and this  lovely and closely comparable Fiio X3, which costs less than one tenth as much (about $200 on Amazon)?

The bottom line is simple.  It is enormously difficult for us to be certain we are truly hearing any difference when hearing the same piece of music played through two different systems, and even if we can hear a difference, it is harder still to know which is best.  Furthermore, there is no way that we can ‘prove’ to someone else that one is ‘better’ and the other is ‘worse’ (and we might even struggle ‘proving’ that to ourselves!).

This is of course fertile ground for people who seek to sell unnecessarily expensive audio equipment that in truth delivers little or any improvement to the music you listen to.  And in a manner similar to the fable of the Emperor’s new clothes, most people are ashamed to admit they can’t hear the difference between the cheap and expensive amplifier or speakers.  This ‘pride’ allows them to be pressured – bullied – into spending more money than they really need on ‘better’ equipment on which they cannot hear any actual improvement in sound quality.

There are also those who persuade themselves they can hear the difference, even though they can’t (ie in cases where there truly is no difference!), and there are still more people who pay attention to the on-paper pseudo-scientific specifications and allow that to shape their decision, preferring to trust a semi-scientific set of statistics rather than their ears.

Other people are hopeful that, even if they can’t hear the difference in sound, it is still beneficial to get the ‘better’ equipment, just in case they learn to hear the difference in the future, or just because the ‘better’ sound is obviously, well, ‘better’, whether you can hear the difference or not, or perhaps simply to impress their friends by having name-brand expensive audio equipment proudly displayed in their living room.

Who is going to contradict any of these people?  The salesman in the store who gets a commission on what he sells?  Fellow ‘enthusiasts’ who want to validate their own unnecessary expenditures by getting their friends to do the same thing?  Industry magazines that would have nothing to write about and no advertisers if they ‘told the truth’ about so-called high-end audio?

Actually, there are some websites out there that try to combat the nonsense and snake oil that is such a part of high-end audio.  Their publishers fight lonely campaigns to distribute the truth, and sometimes do so well, but sometimes end up straddling an uncomfortable middle position that doesn’t quite go far enough in demolishing some of the more fantastic claims made.  Here’s an interesting article, for example, that seems to reasonably conclude that a $2 chip already in your computer can provide the same quality audio as an external $2000 ‘DAC’.

Such a finding should be headlines across the industry, and the people promoting the $20, $200 and $2000 DACs should be castigated and laughed out of the market place.  But in fact, this is a hidden truth that few people dare even whisper, let alone proudly proclaim.

There is only one person who has your best interests at heart.  That person is none other than you, yourself.  But, as we’ve already said, your own hearing is imperfect and subject to perceptive biases and flaws.  Fortunately, there’s a way you can bypass these biases and flaws and end up with a solid determination as to the differences (or, more likely, the lack of differences) between different audio equipment.

We’ll explain how to do that in the next part of this series on high-end audio.  But first, enough talk.  Let’s show you, and allow you to directly understand how limited your hearing is.

If possible, play these following tests through a good set of headphones – they’ll give you a better result than if you just play through regular speakers or, worst of all, the tiny things built into your computer.  (We’ll comment on good headphones in a future article, but for an excellent value mid-upper quality set of headphones, you can’t go far wrong with the Sennheiser HD-558 headphones, currently priced at about $125 on Amazon.)

The Upper Limit of Your Hearing

We first suggest you go to this website and/or this website and see what the upper limit of your hearing is.  In my case, it seems I start to fade away to nothingness at about 13 kHz.  I’ve lost half an octave of hearing over the years.

The point about this first test is to pose the question – what is the use obsessing about highest frequency response if you can’t hear anything over something in the low teens of kHz?

To put your upper hearing limit into context and to help you answer the question just posed, try this test, which allows you to hear a mix of frequencies with and without the highest frequencies included.  Do you hear any difference?

The Lower Limit of Your Hearing

This test is more just for interest than to explain a point.

Here’s an interesting page that allows you to hear sounds as low as 10 Hz.  You’ll probably only start to sense sounds at 20 Hz or possibly 30 Hz, depending on how good your speakers/headphones are.

How Much Dynamic Range Do You Need

Now for another practical test.  The ‘in thing’ in digital audio these days is to go for 24 bit sampling depth, so as to give a 144 dB dynamic range between the loudest and the quietest parts.  Needless to say, both the equipment to play 24 bit music and the recordings themselves are considerably more expensive than ‘normal’ equipment and recordings.  CDs and most digital sound files offer 16 bit sampling which gives in excess of 96 dB of dynamic range.  Let’s see how much dynamic range you need.

Go to this page and work through the examples.  You’ll see the most extreme example is only a 78 dB dynamic range (which in digital terms would be 13 bits), and for most people, even that is ‘too much’ dynamic range for most purposes.

Now ask yourself the question ‘If I can’t even benefit from 13 bits/78 dB of dynamic range, why do I need to pay extra for 24 bits/144 dB?’.  Surely the ‘standard’ 16 bits is more than enough.

How Flat Do You Need Your Frequency Response

Another factor when evaluating the sound quality of a recording is how flat a frequency response is created when the music is played back.  You don’t want to have any peaks or troughs at certain frequencies, which would otherwise cause unnatural coloration of the sound (like listening to it through a tube, for example).

Many companies claim that their gear is capable of playing back a full range of frequencies between about 20 Hz and 20 kHz.  But the key part of this claim, not so prominently featured, is what is the degree of peaks and troughs over that frequency range – is it a perfectly flat frequency response, or does it have significant rises and dips?  Electronic equipment is generally reasonably flat in frequency response, but speakers and headphones are notoriously un-flat.

How small a difference in sound levels can you hear?  One decibel is generally considered to be the smallest difference most people can hear, but some people are more sensitive and others less sensitive.  This test enables you to ‘calibrate’ your own sensitivity to volume changes.

Some Fun ‘Party Trick’ Tests

Now for some fun ‘tests’.  We’ll first take you to a webpage that has a soundfile on it.  It is a distorted recording – play it, but don’t look at the comments that pop up or else it will give the game away.  Chances are you can’t understand what the person is saying.

Please keep playing, to have the words revealed to you, and then for an astonishing revelation.  Click here for this.

What this shows you is how our ears and our brain’s ability to focus on and filter out sounds is very much dependent on how our brain has been ‘pre-programmed’.

There’s a final part to this fascinating experience.  Go away and come back in a day or week or so, and play it again.  Chances are, you’ll have forgotten your ‘programming’ and the distorted version sounds unintelligible again, until after continuing to play the file, when your brain is reprogrammed again.

Want some more?  Here’s a great Youtube video full of amazing audio illusions, (sounds that seem to be going endlessly up in frequency, sounds which people can’t agree upon if they are going up or down in frequency, sounds which vary depending on what you are looking at, and much more) and if that’s still not enough, Google can bring you gazillions more.

The ability to be tricked and what we hear seems to vary depending on our cultural background and even if we’re left or right-handed (here’s the website of a UCSD professor who has made a study of such things).  It makes no sense that a left-handed person would hear something differently to a right-handed person, and that’s probably the key conclusion to seize upon.  Much about our perception of sounds truly does make no sense.

Audio trickery isn’t only something that is fun(ny), and neither is it something exclusively used by audio charlatans.  It is also used in a more bona fide manner to simulate stereo and 3D sounds, and to compress audio by removing the parts of the sounds that aren’t ‘important’ and which don’t register so much in our perception (ie MP3 files).

Implications and Conclusion

So, after all this, you really want to make buying decisions, possibly for audio equipment costing thousands of dollars, based on your ears alone?

And therein lies the greatest paradox of all.  We sense the unreliability of our own audio perceptions and our inability to discriminate between good and bad sound, so we turn to other people – but they are necessarily people who have the same hearing weaknesses as us, and quite likely with vested interests that conflict with our own desire to buy sensibly and appropriately – and accept their recommendations over our own perceptions.

Is there a better way?  How can you really and realistically make decisions about audio equipment and recorded music quality?  Fortunately, there is a way that neutralizes many of these issues.  We’ll explain more in the next part of our series.

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  3 Responses to “You Can’t Trust Your Ears – Or Anyone Else’s”

  1. […] wrote before about how our hearing is imprecise and easily tricked.  If you’ve not read that article yet, and not yet done some of the hearing self-tests […]

  2. […] quick easy proof, visit our page ‘You Can’t Trust Your Ears‘ and try out some of the audio tests midway down the page to quantify exactly how […]

  3. […] lp records, you might like to first read this article I wrote a few years back – “You Can’t Trust Your Ears – Or Anyone Else’s” and then perhaps browse through other articles in my collection of High End Audio […]

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