What’s The Problem?

The audio world has some interesting problems. A particularly vexing problem, which we generally don’t think about much because it makes our heads hurt, involves what we call “audibility.”

This problem arises a lot as we introduce higher resolution, greater bandwidth and improved other audio qualities to our audio systems. We want to know: can we hear the difference? If we can, then we say such an improvement is “audible,” and if we can’t, we say it isn’t. Pretty simple, right? Well, actually, maybe not so simple! That’s the problem!

The question of “audibility” is important. Particularly during times when the technology is improving rapidly, we need to know: how much technology is enough for us? Can we “hear” 24-bit audio, as opposed to 16-bit or 20-bit? Can we hear 192 kHz. sampling rate, as opposed to 32 kHz., or 48 or 96? Why spend the money on gear that yields resolution and bandwidth that may far exceed what we really need?

There is a segment of our industry inhabited by a group of individuals called “audiophiles.” They are, for the most part, individuals with a real passion for their playback systems. They really get into this “audibility” business. Fascinated by little modifications called “tweaks,” they do all sorts of apparently loopy things, including such things (over the years) as painting CDs green, getting “special” high-performance cables at $500/foot, worrying about which way the audio “passes” through the cable, hell, even worrying about whether or not the cable is lying on the floor or being held 3” off the floor by the use of little standoffs! All of these things are undertaken for the express purpose of “improving sound quality!”

Before you start smirking about how loony these amateur guy/gals are, understand that the recording world is just as loopy and obsessive. We are hung up on 24-bits, 192 kHz. digital audio, pure tube-amplified analog audio, vintage hardware which sounds better, jitter, early reflections, impulse response and time smear, to mention a few things. We casually note that MDM X sounds terrible, while MDM Y has “really good converters” (which is code for “sounds real good!”).

So, what’s the truth? Can we hear the effect of these things? If so, how much?

This is where the Cult of Golden Ears comes in. (This cult is not to be confused with my Golden Ears Audio Ear Training - I actually adopted the title because (a) it was a goof, and (b) I live with Golden Retrievers!) There are a bunch of people who either appear to or claim to have exceptional hearing (“hyperacute,” a friend calls it). We’ve all heard Golden Ears stories, about guy/gals who have hearing so sharp that they can hear the effect on their audio system of going from Bakelite to titanium knobs! Golden Ears types are ‘sposed to be able to hear REALLY SMALL differences, and make comments like “Sounds a little fluffy - I think the build-out resistor on Channel 2 is a couple of ohms low,” “Gee I hate the sound of tantalum capacitors,” or “Uh-oh, the dither on the 24th bit just dropped out. They must’ve used the digital fader.”

So, by report and legend, it appears that some of us MAY hear these things. So, what does that mean? If SOME of us can hear the sound of a wire with reversed direction, should we specify wire direction throughout our system? If some us can hear the sound of tantalum capacitors, should we replace them all? It’s an obsessive business. But how far is going too far?

One of the things I do for a living is subjective audio testing. Clients bring me hardware and/or software and ask me to find out things about it, such as “Is our new 27-bit A-to-D converter audible, compared to our competition’s 24-bit converter?” or “Will people prefer our new Grungetone 55 to the current industry favorite Fuzzwart?” I’m supposed to give them answers such as “There is an audible difference between the 27-bit ADC and a stock 24-bit,” and “73.2% of listeners prefer the Grungetone 55 over the Fuzzwart.” If I’ve done my work well, these answers should be reproducible, which means that in application, the client will find my assertions prove predictably true. On that basis, they can claim audible superiority for 27-bit ADCs and/or Grungetone 55s.

The actual technical process of subjective testing is interesting, and I’m planning on writing an article on it. However, that actual testing process is beyond the scope of this article. Here, we first need to have to look at some of the issues that come up surrounding such testing. We need to consider what it means for something to be “audible.”

This is a tough question. Simple, common-sense ways of testing turn out to give widely varying results, and usually prove to be open to challenge for a zillion different perplexing reasons. Part of the problem is semantic and philosophical, and part of the problem is psychological. Let’s talk.