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Critical Listening
By Ron Goldberg
 


Hearing it all is an acquired skill
by Ron Goldberg

 
The most important participant in a musical performance is the audience, or so it's said. Musicians might not agree, but most audio manufacturers like the idea. For their performances, listeners are the only participants that really count.
It's also said (and said again) that these same listeners own the finest test equipment known to audio -- two ears. Who would disagree? For years, designers have charted state-of-the-art TEF measurements and head-related transfer functions, all in a quixotic effort to comprehend and quantify auditory perception. Let's give them a hand, but technoloy isn't biology, and acoustics isn't hearing. Even people with average ears seem to be able to perceive sound in ways that are well beyond the understanding of test equipment.
That's because ears don't work independently of an individual's overall aural perception. Sound and music only become sound and music to us when sifted through the complex electrochemical alchemies that run through our own unique neural networks. And that's before you take into account more unclassifiable factors, such as an individual's mood or predisposition -- never mind taste. Machines can be taught to measure sound, but only humans can hear.
This kind of hearing -- real hearing -- is what both music and audio are all about. And the ability to concentrate this hearing is what's called critical listening ability -- a golden ear, if you will. Musicians have it. Recording engineers have it. Your audiophile friend whose opinion you respect has it. You probably have it too, or why else would you be reading a magazine like this one?
If you think you don't, maybe it's because you've just never given it much thought. Like it or not, we live in a culture where hearing is taken for granted. To us, seeing is believing. American children get a cursory hearing test in kindergarten: raise your left hand if you hear something in the left earcup, then for the right. Barring deafness, that's the last attention some of these ears ever get. That's unfortunate, because often the difference between "golden" ears and the other kinds isn't capability so much as awareness. Most of us are born able to hear everything. But because hearing is so taken for granted, few of us learn to listen.
Photography, the visual equivalent of audio, makes a good analogy. Show two people the same photo and one person might judge it solely by its subject material, i.e.: this is a pretty picture of a seascape. Another person sees the same photo and notices the sky is grainy, the water's blurred and the color of the sand is off. The difference is a discerning eye, not visual acuity. In terms of seeing, most of us can easily make these distinctions -- the difference between red and orange is obvious. But even though most people can hear the difference between the auditory equivalents of color, shade and texture, the average listener isn't always aware of how to recognize or describe them.
 
How then does a listener practice these skills and maybe even apply them to the critical evaluation of audio gear? One good way is to familiarize yourself with how individual musical instruments sound. Every instrument, from a pennywhistle to a Marshall stack has its own unique timbre. For example, air blowing through a flute produces almost-perfect sine waves, meaning that the flute's fundamental pitch is relatively uncolored by harmonic overtones -- a "pure" sound. Digital samples notwithstanding, nothing else but a flute sounds exactly like a flute. A clarinet produces more of a square wave, with odd harmonics creating the characteristically hollow tone. A bow across a violin produces a sharp sawtooth wave, accounting for the string's "buzzy" timbre, while the clang of a gong produces all sorts of aperiodic waveforms at different amplitudes and frequencies.
You can get to know the sonic character of different instruments by listening to solo recordings, or better yet, by actually playing an instrument yourself. Once you're focused on the what sounds of instruments are, the ability to follow them in any musical context becomes second nature. Not only is there a heightened appreciation of the music itself, but it becomes easier to judge how well stereo gear reproduces these sounds.
As an example, the next time you audition equipment, try listening to a jazz arrangement that features doubled lines, where two different instruments play the same passage in unison. Can you easily follow either the trumpet or the sax, or do the two blur together? Orchestral music often presents the same situation, with two or more instrumental groupings playing as one. Are the woodwinds separable from the strings? If they're supposed to blend seamlessly, do they? Good equipment playing good recordings can easily display these distinctions. You can usually hear them clearly when you deliberately listen for them.
Beyond timbral recognition, there's the spatial perception of sound, which is a lot harder for audio equipment to recreate. When we hear, we're receiving signals in a 360 degree pattern, with sound waves bouncing and diffracting off our outer ears and even our skulls before being "inputted" as raw auditory information. A single pair of speakers can only try to approximate this sensation, but good recordings contain a surprising amount of spatial cues. Studio engineers carefully place their microphones to create a specific sonic perspective -- close, far, intimate, detached. Does the playback equipment give you a clear sense of it?
Listen to an orchestral disc -- where are you "sitting" in the sonic auditorium? Front row? Balcony? Back row? If you're a concert goer, you already know how seating location figures in the sound. Does this flavor come across convincingly on the recording? Some of the newer equipment tries to simulate these psychoacoustic cues with digital signal processing or additional speakers. These settings can be fun, but a good two-channel system should give you a feel for the recorded space without DSP and its attendant degradations.
A sense of balance is important to any musical performance, and likewise, to the audio chain. When listening to an ensemble, you should be able to follow any single instrument without difficulty. If one instrument sounds inordinately louder or more present than the others, it's possible that the component(s) you're auditioning unduly emphasize its frequencies. Of course, there may be other factors at play here, like the engineer's intent (or non intent) or the acoustics of the listening room. To answer this question, compare different components and see if the anomaly remains constant. Be sure to focus on the same problem with the different components, which is the only realistic way to judge one against the other.
Beyond the issue of what to listen for, there's the question of what to listen to when performing your auditions. The most obvious advice is to listen to the same recording on the different components -- you'll need a stable reference point. While it may be true that some speaker designs are better suited for one type of music than another, you can't compare apples to oranges, i.e.: jazz on one system, pop or classical on another. Listen carefully to specific tracks on your chosen discs. Isolate a particularly telling passage, and try as best you can to memorize its quality. Only then should you try the same music out on another system, and then as soon after as possible, while your sonic memory is still fresh. Developing this kind of memory takes practice, but it's an essential auditioning skill.
Unfortunately, not all hi-fi dealers are equipped to make proper comparisons along these lines. Many, for example are set up with electronic switchpads for an A-B comparison. Unless the switching is completely transparent, it may not be an effective method at all. Our ears like amplitude, and one component played even a shade louder than another will often sound "better." For this reason, a more efficient speaker will usually outshine a less efficient one in these A-B tests, as will a more powerful amp than a less powerful one. If the dealer's switching equipment can't compensate for these differences (some can), you're better off listening to one component thoroughly, then the next one, instead of switching back and forth.
Unless you're lucky enough to have perfect pitch or a musical training, ear awareness rarely comes naturally. Listening is like any acquired knowledge; nobody's born knowing the subtleties of the five senses. Sometimes you'll curse your own awareness -- once you know what good audio can sound like, your checkbook tends to lose weight through upgrades. But through good equipment, it's really possible to have music in your home that's just like the real thing, and sometimes even better. Isn't that the whole reason why you care about this stuff in the first place?
this story originally appeared in high performance review, june 1993.


 


 
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