How Humans Conquered Echo

A brief history of artificial reverb in music

reverb 615 flickr user  Adriano Agulló weir.jpg

When the Harmonicats' "Peg o' My Heart" was released in 1947, the harmonica instrumental would have been just another catchy tune on the radio were it not for the surreal, atmospheric reverberation that drenched it. Producer Bill Putnam's use of an echo chamber (specifically, a microphone and loudspeaker placed in the studio's bathroom) was probably the first artistic use of artificial reverb in music, and it lent an eerie dimension to the song. The record hit No. 1 on the charts 65 years ago today and stayed there for most of the summer.

No mere gimmick, Putnam's innovation begat a new twist in humans' ongoing effort to tame the forces of echo, a quest that has shaped the architecture of ziggurats, cathedrals, and concert halls. As it happened, the otherworldly reverberations of the lavatory at Putnam's Universal Recording studio in Chicago fit nicely into this millennium-long tradition.

"My dad was really intrigued by artificial reverb," says his son, Bill Putnam Jr., who took over his father's business with his brother, James Putnam. "I would say haunted, but not in a bad way."

Arguably the oldest and most universal sound effect in music, reverb has informed the spiritual grandeur of 10th-century plainsong and the Rastafarian message of early dub. Even the guitar solo of every 1980s power ballad bears reverb's angelic touch. Yes, reverb makes music sound better (when done right), but it goes well beyond what we can reasonably ask of any studio trick: It suggests that there's something beyond ourselves. In their book, Spaces Speak, Are You Listening? Barry Blesser and Linda-Ruth Salter write that early humans considered echoes "the sounds or even voices of spirits from a world beyond the cave wall." Shouting "Hello!" in a stairwell might not convince you that angels await on the next floor, but a voice unattached to any person ringing in the air for a few seconds certainly suggests some other presence.

(A quick taxonomy: "reverb" and "echo" are often used interchangeably, but really echo is when sound repeats—"Hello!... hello!.. hello!"—and it almost always happens outside. Reverb is an indoors phenomenon that occurs when there's not enough distance for delays, and it results in a continuous ring until fading. By "artificial reverb," I mean any reverb that doesn't naturally occur in a performance—or isn't reverb at all, but an electromechanical simulation of it).

For most of history, musicians were at the mercy of reverberation, and they adapted their work accordingly. Many composers, including J.S. Bach, frequently wrote music in ways that exploited the specific acoustics of certain buildings. Gregorian chant likely developed because of cathedrals' acoustic properties; the long reverberation times (often up to 10 seconds) limited the number of notes that could be sung before blending into a messy sonic mix—a phenomenon that likely sped up the arrival of polyphony.

But with artificial reverb, studio engineers could bend reverb to their will. Often they did so to mimic the sounds of great concert halls and cathedrals, but for some, artificial reverb allowed them to become the virtual architects of spaces that could never exist in the real world. They could create the aural equivalent of M.C. Escher drawings.

Stuart Hallerman, owner of Avast! Studio in Seattle, where Fleet Foxes, Band of Horses, and Earth have recorded, says both approaches have their place. Sometimes he uses reverb to create a "documentary-style" recording with a realistic sense of space. "But some mixes I do as abstract art," he says. It depends on who's in the studio that day. He'll create a reverb sound similar to a small club or garage for a punk band and something a little more mysterious for a band like drone masters Earth. Fleet Foxes, whose members have said they aim for the "transcendence" of religious music without the actual religion, pull all the stops when it comes to reverb. "They have a sweet tooth for that ear candy," Hallerman says.

Fleet Foxes are hardly the first to borrow reverb's splendor to hallow their secular pop. While "Peg o' My Heart" is widely considered the watershed moment for artificial reverb, musical firsts are rarely so cut and dry. Mitch Miller claimed his engineer, Robert Fine, was the father of artificial reverb; Fine was directed to create a "halo" around a singer's voice—also in 1947. "So he put a speaker and a mic in a toilet, and that bit of added resonance gave us the halo we wanted," the late Miller told the Boston Globe in 1996. Of course, reverb's spiritual associations go back much further. Some archaeoacoustics researchers believe prehistoric shamans communicated with animal spirits in parts of caves that produced the richest echoes. Recent research suggests that Stonehenge derived some of its mystery from the distinct reverberation patterns that the structure produced.

CONTROLLING A STRUCTURE'S SOUND REFLECTIONS involved a lot of guesswork until the turn of the century, when Wallace Sabine turned acoustics into a science with an equation that determines the exact qualities of a building's reverberation. The first result of this formula was his work on the Boston Symphony Hall, now considered one of the high watermarks of concert hall acoustics.

But recorded music's rise in popularity brought with it the question of how to recreate the sound of physical space. Countless methods emerged, some ingenious. That ghostly sound of Robert Johnson's recordings? He sang and played guitar while sitting in a chair facing a corner of the room (the technique is called "corner loading") Guitarist Duane Eddy used a 2,000-gallon water tank from a scrap yard, placing a speaker on end of the tank and a microphone on the other. Capitol Records built its concrete echo chambers 30 feet beneath its studio.

None of those solutions are particularly portable, which in itself presents a problem that various contraptions sought to correct. There was the widely used EMT Reverb Plate, for instance, and much less-used oil can delays. Tape delay devices such as the Echoplex and the Roland Space Echo derived from the "slapback" echo technique made famous by Sam Phillips at his Sun Studio. Essentially a tape machine with two playback heads, one that repeats milliseconds after the first, it defined the sound 1950s rock and roll. Along with Chet Atkins, it was Elvis's guitarist, Scotty Moore who brought artificial reverb out of the studio and onto the stage with the EchoSonic, an amp with built-in reverb designed by Illinois music store owner Ray Butts.

Spring reverb, which gets its very distinct sound from a set of springs, was the sound of the 1960s. This technology originates from Bell Labs, and was first musically employed by the Hammond company after church organists complained of the flat sound of earlier models. To modern ears, spring reverb sounds nothing like a cathedral, but this was no problem for Dick Dale and other surf guitarists, who used the effect to create splashy sounds evoking SoCal waves. King Tubby and other dub pioneers used their spring reverb units as if they were instruments themselves, tinkering with them to coax out ever stranger sounds, sometimes throwing them to the floor to create thunderous echoes.

So much effort for a sound effect. Why bother? I asked Sean Costello, who describes himself as a "creator and historian of reverb algorithms."

"By adding reverb, we put the instruments and voices into a more 'natural' context," he says. "Things sound like how we know the world to be."

Costello, who thinks about reverb a lot, believes an evolutionary adaptation is at work.

"A sound that is 'reverberant' suggests that it is a certain distance from the listener, and this is important when you are trying to avoid being eaten," he says. "A lion roar that is reverberant suggests that the lion is probably far away. A lion roar without reverb suggests that the lion is probably far too close."

Whether in the jungle or not, a lack of echo can discomfit. Spend some time in an anechoic chamber—a space entirely devoid of echo—and it's clear how important sound reflections are to our well-being. Speech seems to die mid-air in the chamber, and it's a jarring experience—anxiety-inducing for some. Similarly, music recorded in "dead" space produces some spooky results.

But spooky can be a good thing. Producer Rick Rubin knows this, and he avoids reverb to great effect. His bone-dry recordings of Johnny Cash are nothing if not haunting.

Digital reverb became the preferred means for creating aural spaces in the 1980s. In recent years, greater computer power has allowed for convolution reverb, a technology that allows engineers to actually sample a particular room's reverb. Audio East's Altiverb, for instance, promises the exact acoustics of everything from London's Wembley Stadium to the caves of Malta to the inside of a Ford Transit van.

I ask Putnam if there's really that much more to do with artificial reverb, 65 years after his father's work with the Harmonicats. To an audio engineer, this is a little like asking if there's any need for new music.

"We live in a world of sound reflections, even if you're not aware of them," Putnam says. "Reverb, real or artificial, just takes us back to that." Some forms of reverb comfort the listeners, he said, giving them a familiar setting. The fun happens when you find a new way to use reverb to "monkey wrench the brain."

"In a lot of ways, creativity is just messing with people's expectations," he says. "Reverb can be that jolt."