What Are Audio Psychoacoustics and Do They Apply to Your Listening Efforts?

Put 10 people in a room and play a song none have ever heard before. It is a pretty safe bet one or two of the 10 will love the song, one or two more may not like it at all, a few will think it is just okay, and several won’t really care one way or another. The same can be said about almost all of our preferences. My wife teases me, because the list of foods I dislike is substantially longer than the list of foods I do like. Why? Simple. It’s called personal preference. As it applies to our audio systems, it is also called audio psychoacoustics, and it plays an important role in our listening practices of the music we play and enjoy. 

What Are Audiophile Psychoacoustics?

Humans perceive sounds in many different ways. Audio psychoacoustics is therefore a study in how sound is perceived by the ear/brain mechanism. It blends, if you will, the study of psychology and the study of acoustics in an effort to understand the physical properties of sound. But equally important, audio psychoacoustics is an examination of how we actually perceive the sounds we hear. 

In simple terms, audio psychoacoustics is the science of sound perception. Hearing in humans is, for one, a mechanical function – sound waves enter the ear canal and are processed by both the outer and inner ear, thus sending signals to the brain. Our ear/brain mechanism, the amazing connection it is, also has the ability to subjectively perceive sound. These perceptions may easily differ widely from person to person. How one person perceives the sound they hear might undoubtedly be quite different than someone else’s perceptions. It is for this reason that one or two of the 10 people will love the song, a couple will likely despise it, and the remainder will have varying opinions, both positive and negative. How we perceive what we hear is a critical factor in determining our musical likes and dislikes. Recording artists know this, and recording studios are well aware of this phenomenon. In fact, studios are constantly working with their artists to create music they feel will be enjoyed and likewise purchased by as many listeners as possible. 

What about audiophile equipment manufacturers? Think they pay attention to how their equipment sounds? You better believe they do. It is called voicing, and this is a standard practice among almost any audiophile manufacturer. In fact, it is not uncommon at all for a group of employees in an audiophile manufacturing company to gather and listen to music on a newly-designed component and then render an opinion on what they liked sonically, what they did not like, and what changes each one feels should be made. Whether or not it is formally stated, each person involved with voicing a manufacturer’s newly-designed piece of equipment is using audio psychoacoustics to make their determination on how something sounds, and what changes are necessary. In both these examples, audio psychoacoustics are actually being monetized. 

Sometimes Logic and Common Sense Do Not Really Matter

Anyone who lives in the Southeast is familiar with our infamous late afternoon summer thunderstorms. We can go from not a cloud in the sky to a full-out torrential rain storm, complete with thunder, lightning and sometimes hail in no time. These storms last for about an hour or less and then the sun comes back out. It was during one of these storms, about 10 years ago, that lightning took out my Esoteric A02 stereo amplifier. After desperately trying and failing to get it working, I reluctantly sent it to an Esoteric service center in California, where I received the bad news. The main circuit boards were fried due to a power surge (lightning) and would need to be replaced. The boards had to be custom-built at the Esoteric factory in Japan and then shipped to the California service center. Time to repair? Three months. Cost? A brutal $3,000. I turned off the rest of the system, unplugged everything, and left my audio room for the next quarter of a year. When the amplifier was finally returned and I got my system back up and running, my music had never before sounded so magnificent.

Logic and common sense tell me my rebuilt stereo amplifier had not changed or improved my system’s sonics in any measurable way. The room size or treatments had not changed. Literally, nothing in the room had been physically moved or repositioned. No new equipment, beyond a rebuilt-to-original-specs amplifier, or revised settings on existing equipment, had occurred. Everything was exactly how it was before. Yet it sounded so much better. I remember being amazed at the incomparable improvements in my system’s sonics. At the time, it never really occurred to me that my system sounded exactly the same. The only change was my own perception of how my music sounded different, even, perhaps, much better. 

Psychoacoustics Play a Part in Our Perception of Musical Reproduction

Our ear/brain mechanism processes sound in measurable parameters, such as frequency, amplitude and time alignment. Based on those criteria, we are instantly able to discern if someone with a high-pitched or low-pitched voice is yelling at us or whispering. We can instantly tell if the thunder we hear is directly above our home or off in the distance and, if so, the direction from which the sound originates, thus defining directionality. 

Mechanical processing allows us to sit in the audience and hear the guitarist on the right of the stage, the pianist on the left and the lead singer squarely in the middle. We can see where the instruments are placed, and we can also hear where they are placed. Same for our audio system’s sonic capabilities, the goal being an accurate representation of what the recording engineer heard when the music was recorded at the studio. These same abilities allow us to discern factors in our audio systems, such as soundstage and imaging, dynamics, clarity, accuracy and frequency response. In short, it helps provide what all audiophiles really enjoy: a completely immersive audio listening experience. 

Yet we are also amazingly able to assess what we hear and instantly place a value on our likes or dislikes of the sound being presented. In the case of music, it is where I feel psychoacoustic principles really apply. Why do I like any one particular song, when someone else does not? Why do I prefer music with a good beat, as opposed to something slow and mournful? Why is smooth jazz my preferred genre above all others? Why, when I was much younger, did I adamantly despised classical and country music and now, to a certain degree, like both? In some ways, this might be likened to the reason why I disliked zucchini for most of my life and now I do not. That, however, is my tastebuds changing. Music is different. 

How we sense what we hear is also a listening experience based on a different set of parameters than mechanical. Our perception of what we hear may be influenced by our mood and how our brain tells us we are feeling at any one point in time. My perception of what I was hearing is likely the reason my system sounded so spectacular after a three-month absence, when logic and common sense tell me it should have sounded exactly the same as before. This is also a reasonable explanation of why, on some days, I happily sit down in the listening chair, select or develop a playlist, or put on an LP, and prepare myself for sonic ecstasy. And suddenly, after just a few minutes, I get the pervasive feeling my system is in no way appealing and does not sound especially involving, at least not at that exact moment, and I turn things off, leave the audio room and wait to fight another day. Try though I might, I cannot think of a reasonably practical reason beyond audio psychoacoustics to logically explain this occurrence. 

Do Audio Psychoacoustics Enter Other Areas of Our Audio Experience?

This phenomenon might also help explain the differences various audiophiles hear in cables. I have always maintained that, regardless of how well cables are engineered and measure electronically and mechanically, unless I hear them, I will always be hesitant about buying them. Cables are undoubtedly one of, if not the most, controversial aspects of the audiophile hobby. Too many audiophile cable companies fail to publish any measurable facts in support of their claims about the performance of their products. For those of us who do believe better cables make a difference, are we hearing an actual or perceived improvement? Could psychoacoustics be the explanation behind why one cable sounds glorious and another one is not really all that spectacular?  Is this the reason behind the mountain of dissent surrounding the validity of audio cables? 

What about the difference between tubed gear and solid state gear? This is a debate which has been taking place since the 1960s when the transistor was first introduced into electronic gear and the term “solid state” was born. Why do we like the purported warm and natural sound of tubes, or the more dynamic and forceful sound of solid state? Is there really an audible difference between the two, or are we being guided by some unseen force that our ear/brain mechanism is mandating we prefer? Could this be simply and easily chalked up to audio psychoacoustics? 

Final Thoughts on Audiophile Psychoacoustics …

The audiophile experience is many things to the various proponents of our hobby. Many of us look to better understand the science behind why our systems behave as they do. We look to electronic principles and physics to explain why one system sounds so different than another. We use this same science to help improve our own sonic system excellence, thereby improving our listening experience. 

It also therefore follows there are other factors at work in our listening experiences. And not all of them can be explained by science, where measurable facts precede rational explanation. It must be conceded, therefore, that at least part of our listening experience is mandated by our perceptions of what we hear. We must accept the fact that, on some days, our systems sound glorious, on others, not as much, and that this is perfectly reasonable and normal. Neither our stereo, nor the space in which it is housed, has changed. Only our perception has changed. And this change, however it is perceived, however slight or monumental, is principally a combination of psychology and acoustics. 

We hear sound in the physical world. How we interpret what we hear is a byproduct of how our brain perceives the various sonic qualities. And just like any of our predilections, what we like is constantly evolving and our preferences will change. It follows, therefore, these changes, regarding our systems’ sonics, are due to audio psychoacoustics. Some days, we love what we hear from our beloved audiophile systems, and some days, by and large, we do not. The best-priced upgrade in the audiophile world is coming back the next day to see how you feel about your hand-curated audiophile system. Chances are it will be different on a day-to-day basis and that is totally okay.