Author: Matt

3D audio with just two speakers

I’m old enough to remember when the term high fidelity still meant something—it set apart audio equipment that had been deliberately engineered for faithful sound reproduction and a high signal-to-noise ratio from cheaper, cruder devices. At a certain point, though, pretty much everything was considered “Hi-Fi”; the new buzzword was stereo. Having equipment and recordings with two discrete channels of audio—conveniently matching the average number of human ears—was seen as the new sign of audio competence. Then there was the shift from the analog world of tubes, tapes, and vinyl to digital—a new standard of audio quality. A few years later, yet another phase: an increasing number of carefully positioned speakers and subwoofers to simulate the 360° audio field of the cinema. And now we’re using sophisticated digital signal processing to get better results with fewer speakers, but most people still seem to think two is too few.

For Those Who Have Ears to Hear…

While the number of speakers in the typical living room has increased since the days of my youth, the number of ears on the typical head has not. Humans somehow have the ability to locate the source of a sound spatially with only two inputs; even with a single ear, most people can pinpoint the direction a sound is coming from. Crucially, this sound-locating ability is not restricted to a single plane; we can also determine if a sound is coming from above, below, or anywhere in between (not to mention in front and behind). No home audio system I’ve ever seen (or heard) addresses the Z axis (up and down)—and neither, for the most part, do cinemas; for the most part, the only way to experience truly 3D sound artificially is to go into a special environment such as San Francisco’s Audium where speakers are physically placed above, below, and all around you.

If humans can determine the location of a sound anywhere around them with just two ears, it’s reasonable to imagine there must be some way of reproducing spatially accurate sound with just two speakers. But what’s the trick? What can ears and brains do that microphones and speakers can’t?

The Ears Have It

A large part of what enables people to identify the position of a sound is attributable to the hardware—the unique shape of the ear folds and ear canal. Because sounds coming from one direction will be reflected and channeled into the ear canal with slightly different characteristics than sounds coming from another direction, the brain is able to use these subtle clues to unconsciously create a mental picture of where the sound must have originated. While digital signal processing equipment can add depth and spatial separation to a stereo signal, there’s a much different and older approach to solving the problem: a method of recording known as binaural audio. A binaural recording is made with two microphones and a two-track recorder, just as a stereo recording would be. The difference is that the microphones are placed inside a dummy head—shaped just like a human head, complete with rubbery ears, sinus cavities, and so on. The microphones are right where the eardrums would be, so the signal they pick up is much closer to what ears would hear. The resulting recording—always most effective when heard through headphones—produces a vastly more accurate spatial rendition than would be achieved by using a pair of conventional microphones.

A well-executed binaural recording can sound shockingly realistic, even if the sound quality itself is not pristine. But binaural recording is appropriate only for live recordings; it’s also inconvenient, expensive (some pro-quality dummy heads retail for over US$8,000), and, frankly, just plain weird—all of which, along with the fact that you need to listen through headphones for maximum impact, helps to explain why you don’t encounter such recordings very often.

Hooked on Holophonics

But there’s a clever, patented variation on binaural recording that claims to go far beyond the simple microphones-in-the-dummy-head approach. It’s called holophonic recording, and the realism it produces, especially in the up/down dimension, is uncanny, eerie…even—as a friend of mine likes to say—freakadelic.

Ordinary holograms are produced by mixing reflected laser light with a second beam hitting an object from another angle; the resulting interference pattern of the two waves is what’s actually recorded on film. Expose the film to the same wavelength of light again, and a 3D image emerges from the interference pattern. Italian inventor Hugo Zuccarelli wondered whether a similar process could be used to record sounds, since after all, sound waves can form interference patterns with each other just as light waves can. His holophonic process starts with a type of binaural dummy head, but it reportedly records the interference pattern formed by mixing the sound with an inaudible, digitally superimposed reference signal. Zuccarelli believes that the human auditory apparatus, when listening to sounds, adds the same signal to the input, effectively decoding the interference patterns previously recorded. All that may sound like a bunch of mumbo-jumbo—and Zuccarelli certainly has detractors who claim “holophonic” sound is nothing more than binaural with maybe a few bells and whistles. All I can say is: hearing is believing. The holophonic recordings I’ve heard are simply remarkable—much more impressive than conventional binaural recordings—but I encourage you to listen for yourself (remember, use headphones!) and form your own opinion.

There is, of course, a little snag. As with all binaural recordings, holophonic sounds lose most of their spatial characteristics when played through ordinary speakers (though Zuccarelli has designed a special speaker system that enables holophonic sounds to be appreciated even outdoors by a large audience). As things stand now, you won’t be able to enjoy a holophonic soundtrack on your home theater system—no matter how many speakers it has—unless you and everyone else watching the film wear headphones. Nevertheless, a number of recording artists, including Michael Jackson, Stevie Wonder, and Pink Floyd, have employed holophonic technology in recordings or concerts, and it has also been featured in both films and commercials. Holophonic sound may be slow to catch on as a mainstream technology, but it’ll make your Surround Sound system sit up and go “Wow.”

Note: This is an updated version of an article that originally appeared on Interesting Thing of the Day on July 17, 2003, and again in a slightly revised form on October 12, 2004.

Image credit: U.S. Patent and Trademark Office

If you’re sick and tired of all these daily observations of anything and anyone (whether serious or silly), today, January 16, is just for you. It’s National Nothing Day, a non-holiday to not celebrate a non-event—and has been since columnist Harold Pullman Coffin declared it so in 1973. So you don’t have to do anything, or celebrate anything, or protest anything today. If you have to watch TV, maybe you should watch the show about nothing, or just go around quoting your favorite line from Game of Thrones.

Image credit: darwin Bell from San Francisco, USA [CC BY 2.0], via Wikimedia Commons

The curious process of canonization

Douglas Adams, whose writings I have always admired greatly, was a self-proclaimed “radical atheist” who nevertheless liked to say that he was “fascinated by religion”—carefully pointing out that interest was different from belief. Although I would characterize my own views in somewhat different terms, I share his fascination with certain religious beliefs that I do not personally hold. One such notion is that of the saint, particularly as the term is used in Catholicism.

Borrowing an expression from the historical canonization process, allow me to play devil’s advocate for a moment. As an outsider, my impression of saints is that the Church considers them to be extra-holy (dead) people to whom God pays special attention, so that by praying to a saint instead of directly to God, you somehow stand a better chance of having your prayer answered. So they seem to function as heavenly lobbyists, and frankly, I would have thought that an omniscient God would frown on such tactics. Presuming, of course, that a departed soul can hear prayers at all, it is unclear to me why a saint would listen to me in the first place if God were disinclined to heed my prayer. And my mind boggles at why saints’ domains of intercession should be so specialized. (Did you know that Isidore of Seville is the patron saint of the internet? No kidding.)

These things puzzle and exercise me. At the same time, I find the whole subject of sainthood extremely interesting. In particular, I always wondered just how it was that someone came to be recognized as a saint, having picked up only bits and pieces of the process in books and movies. After doing a bit of research, I think I can give a very rough (and, I hope, approximately correct) outline of the path to sainthood. But before I describe the current process, I need to go back quite a few centuries to provide some background.

Saints Alive

As I understand it, the word saint (from a Latin word meaning “holy”) was used in the New Testament simply to denote a righteous person (living or dead). During the early centuries of the Christian Church, the term was applied fairly freely to any number of people, and the practice of praying to particular saints after their death gradually became an accepted part of religious life. Eventually, bishops reserved the authority to decide who should be considered a saint, but such proclamations were considered valid only for that bishop’s local area. By the 10th century, the Church realized that very uneven standards were being applied, and that rather questionable characters were being called saints—even some who may never have existed. So the process was officially codified for the first time, with the pope assuming sole authority to proclaim someone a saint. Although this title was given to some who had been called “saints” before, many didn’t make the cut. (St. Christopher was among these. Although never canonized—formally declared a saint—his feast day continued to be listed on the official Church calendar until 1969.) The rules for canonization were refined and improved over a period of several centuries.

The original process was an enormously complex and lengthy one. Church investigators collected extensive evidence about the person’s life and death—including, especially, any writings the person left. But the crucial test was that of miracles. It was not necessary that a person had performed a miracle while living (though such events certainly helped the cause). Rather, evidence had to be found that after the person’s death, someone had prayed to them—and only to them—and that a miracle had subsequently occurred. The number and nature of required miracles varied according to the circumstances. Many of the earliest saints were martyrs—those who had not only led holy lives but who had demonstrably died for their faith. Martyrs were put on the fast track to sainthood, with less-strenuous requirements—including fewer (or in some cases, no) miracles.

When a certain amount of evidence had been collected, the person was beatified, at which point he or she could be referred to as “the Blessed So-and-So.” But before sainthood could be granted, proof of one or more additional miracles was required. In addition, the life of the saint-to-be was subjected to the utmost scrutiny, with an appointee of the Church (commonly known as the “devil’s advocate”) digging up and pointing out any potential flaw or shortcoming, no matter how small. If this person, who functioned very much like a prosecutor in a trial, was unable to prove his case “against” the beatified, sainthood could be granted.

You will notice, of course, that I speak of all this in the past tense. In 1983, Pope John Paul II simplified the process of canonization tremendously—and eliminated the position of “devil’s advocate.” Now, in general, beatification requires an unblemished biography—with ample indication of the individual’s devotion to the Church—plus one posthumous miracle. Canonization requires a second miracle. Although the process is not even supposed to begin until at least five years after a person’s death, the pope can waive that requirement at his discretion, as he did with Mother Teresa.

It’s a Miracle

This business of proving that a saint was responsible for a miracle is particularly fascinating. The Church adopts a stance of skepticism toward all such claims, and has an entire staff of scientists and doctors who attempt to disprove the miracles—or to find alternative explanations. Most “miracles” are miraculous cures, and in such cases, the Church requires that a board of five doctors unanimously agree that no other explanation exists. Moreover, the cure must be complete and instantaneous; if the illness was cancer, a waiting period of 10 years is required to be sure the disease hasn’t merely gone into remission. Of course, proving that a particular saint was responsible for a miracle (having interceded with God on someone’s behalf) is not such a scientific undertaking. What if, for example, a neighbor prayed to another saint but didn’t tell anyone? What if—heaven forbid—the “miracle” occurred due to perfectly natural causes that simply escaped the scrutiny of the examiners? When all is said and done, no formal process, however detailed and rigorous, can completely eliminate the need for faith.

When all the tests have been passed, the pope proclaims, infallibly and irrevocably, that the person is a saint, and, in fact, always has been. The pope’s declaration does not, according to Catholic dogma, make someone a saint, it only acknowledges this fact officially. The faithful may honor and pray to a saint, but not worship a saint, as worship is to be reserved for God. Likewise, a saint does not actually perform a miracle but rather entreats God to do so. But in real life, these fine distinctions are sometimes lost, turning saints, for all practical purposes, into demigods.

Thanks to his newly streamlined process, Pope John Paul II declared nearly 500 people to be saints—many more than all his predecessors combined. Not to be outdone, Pope Francis has declared almost 900 people—including Pope John Paul II and Mother Teresa—to be saints as of early 2019. This seems rather excessive to me, but then, having any saints at all strikes me as an unnecessary complication in an already complex religion. I suppose the optimistic view is that this is a reflection of an ever-growing number of virtuous people in the world. But I can’t prove that; you’ll have to take it on faith.

Note: This is an updated version of an article that originally appeared on Interesting Thing of the Day on March 19, 2005.

Image credit: Aleteia Image Department [CC BY-SA 2.0], via Flickr

The English language Wikipedia came to life on January 15, 2001, so it’s now old enough to vote! Although I can identify numerous shortcomings of the Wikipedia—and generally try to avoid using it as a reference for articles here if I can find a better alternative—it is nevertheless an incredibly valuable, and occasionally accurate, compendium of knowledge, and I’m glad it exists! Perhaps one day I’ll be considered sufficiently notable to get my own page.

Image credit: Wikipedia [CC BY-SA 3.0]