A Brief History of Loudness

by Bradley Denton

     My primary Wild Cards character, Freddie “Amplifier” Fullerton, the World’s Loudest Boy, has starred in one Wild Cards story so far (“Naked, Stoned, and Stabbed,” Tor.com, October 16, 2019), and he’s slated to appear in the upcoming “Echoes from a Canyon Wall” (PAIRING UP, Bantam, publication date TBA).  I’ve balked at calling Freddie an ace, but longtime Wild Cards author Caroline Spector assures me that Freddie’s Wild Card power absolutely does make him an ace, without question.

     However, I still don’t think of Freddie that way.  His power is largely out of his control, and most of the time it produces only minor effects.  Of course, there are exceptions in extreme circumstances . . . and in those cases, he’s often knocked into a coma.  So it seems to me that he’s more deuce (or perhaps “collateral damage”) than ace.

     Freddie’s power, you see, is that he has an exceptionally loud voice – but only if he’s hit with physical force or an electrical shock.  And then he has no choice but to release an amplified shout right at the moment when the damage occurs.  For example, if he’s punched, he’ll cry out in surprise or pain, as most people would.  Freddie’s shout, though, is far louder than a normal person’s shout, and might result in hearing loss or other physical trauma for anyone standing in front of him. 

     The loudness of Freddie’s shout increases exponentially as he’s hit harder.  A slap in the face might make him yell loud enough to break a window, but if he were struck by an automobile traveling at, say, 40 mph, he might – if he’s aimed in the right direction, and if he’s close enough – blow up a lumber yard.

     That’s a nod to the fact that real-world sound pressure measurements, expressed in decibels (dB), work on a logarithmic scale.  And if you know how to do the math, measurements of sound at a distance, where the perceived loudness is weaker, can be extrapolated to determine dB levels at the source.  

     It’s complicated stuff.  Roughly, though (and at the risk of being terribly wrong by being not quite right), dB measurements are all relative to the quietest sound a human ear can hear (20 micropascals of sound pressure in air), which is about a trillion, or 10 to the 12th power, times quieter than the sound pressure at which hearing damage can occur.  10 to the 12th times louder than 20 micropascals of pressure is about the same loudness as the siren of a fire engine, and a sound of that volume serves as a benchmark of 120 dB (since decibels are expressed as 10 times the log, or in this case, 10 times 12).

     Using that scale, human speech, as perceived by someone standing right beside the person speaking, measures 25 to 35 dB; an animated conversation between two people might reach 60 dB; your mother shouting your full name, including your middle name, could reach 105 dB; and the sudden, explosive noise of a shotgun being fired might hit 160 dB.  And since the dB scale is logarithmic, every 10 dB increase means that the corresponding sound pressure is ten times louder.  So 60 dB is ten times louder than 50 dB, and it’s 100 times louder than 40 dB.

 The loudest measured sound in human history occurred on August 27, 1883, when the volcano Krakatoa, located in the Sunda Strait between the islands of Java and Sumatra, went – to use a technical term – kablooey.  Four gargantuan explosions burst the eardrums of sailors on a ship more than three miles away, created devastating tsunamis, and ultimately killed over 35,000 people.  Some 2000 miles to the southeast, in Western Australia, Krakatoa was heard as a sound like that of distant artillery.  And at weather stations around the globe, the eruption was detected as shifts in barometric pressure that circled the planet at least three times (and up to seven times, depending on your research sources).

     Based on extrapolative calculations like those mentioned above, the explosion of Krakatoa has been estimated to measure 310 dB at the source.  But it’s important to note here that anything over 194 dB (in air) isn’t even considered to be “sound” anymore.  At that point, a vacuum forms between the waves, and their amplitude can’t increase.  So instead, “sound” over 194 dB distorts the wave and is called a shock wave.  But the power of a shock wave diminishes with distance until it’s eventually perceived as sound again – such as when the destruction of Krakatoa was heard in Western Australia.  (Note: The sailors with the burst eardrums, over three miles distant from Krakatoa, experienced at least 202 dB.  They didn’t really “hear” anything, but were hit with a shock wave.)

     Estimates suggest that the next loudest sound in human history, after Krakatoa, was also due to a natural phenomenon.  But it wasn’t a volcano. 

In June 1908, a shock wave knocked a man from a chair on his porch in Siberia – because 40 miles away, a meteor entering Earth’s atmosphere had exploded, causing what is now known as the Tunguska event.  Based on its destructive power (as seen in photographs of hundreds of acres of flattened trees), the Tunguska explosion is estimated to have generated a shock wave with an initial pressure of 300 dB – in other words, about a tenth the power of Krakatoa. 

     A more recent Russian meteor detonation over Chelyabinsk on February 15, 2013, generated a measurement of 90 dB at a distance of 435 miles, which would put the sound pressure at about 180 dB at 3 miles from the source.  That’s not as hard-hitting as Krakatoa or Tunguska, but it’s still in the big leagues.  Dozens of people in the area rushed to their windows because of the exploding meteor’s bright light, and then were seriously injured when those windows shattered from the shock wave that followed.  

     Along with volcanoes and meteors, the Earth’s crust chimes in from time to time.  For example, a 5.0 Richter earthquake can create a shock wave, at its epicenter, that might hit about 235 dB.  That’s 10 to the 13th power (ten trillion) times louder than your mother can yell your name.

     After volcanoes, exploding meteors, and earthquakes, we have a number of human-made events and items that can blow you over or bust your ears.  The most horrifying of these was the biggest hydrogen bomb ever tested – the Soviet Union’s “Tsar Bomba,” detonated over Novaya Zemlya in the Arctic Ocean on October 30, 1961, which created an initial shock wave of 224 dB.

 In 1969, in the U.S., the Saturn V rocket that launched humans to the moon generated 204 dB at blastoff. 

Fourteen years before that, also in the U.S., a propellor-driven experimental fighter airplane known as the XF-84H “Thunderscreech” did its best to deafen ground crews with a noise reaching 200 dB . . . because the aircraft’s prop tips rotated at 900 mph, producing a constant sonic boom.

    And finally, in the Netherlands, the European Space Agency currently operates an enormous audio chamber known as the Large European Acoustic Facility (LEAF).  There, satellites are tested for structural integrity by being exposed to the kinds of sound waves they will need to withstand when they’re blasted into space.  Fortunately, since most rockets today aren’t quite as loud as the Saturn V, LEAF only needs to reach about 154 dB.

The XF-84H earned the nickname “Thunderscreech” because of the piercing howl of of it’s engine during startup. (U.S. Air Force)

     But all of those noisemakers are non-biological.  When I was trying to figure out how loud Freddie Fullerton could get, I was more curious about how loud a sound an actual living creature might produce.

  The loudest I could find was the mating call of the largest mammal alive, the blue whale.  Sound in water isn’t measured the same way as sound in air, but even taking that into account, a blue whale seems to be able to shout the cetacean equivalent of “I’m looking for love!” at about 188 dB.  And it must work, since blue whales are still making more blue whales.

     However, I wanted to find a loud animal that was closer to the size of a human being.  Because I didn’t want to make Freddie as big as a blue whale.

     That quest led me to the loudmouthed primates of Central and South America, the howler monkeys.  The “hyoid bones” in these guys’ throats have evolved to form a resonating chamber that amplifies and projects their cries with haunting and headache-producing efficiency.  The cry of a howler monkey can be heard at a distance of three or four miles, and when a group of them get together, they might wake up the neighbors ten miles away. 

     After all, just one howler monkey can hit 140 dB, which is not too shabby for a 15- to 20-pound animal.  If a howler monkey were the size of a human, imagine what it could do.

     Well, then, just how loud can a plain old human voice get without the help of hyoid-bone evolution or the wild card virus?  

     So far, the loudest measured human scream – emitted in order to set a Guinness Book World Record – was screamed in the year 2000 by a lady named Jill Drake, a classroom assistant from Tenterden, Kent, United Kingdom, whose shriek measured 129 dB.  (Remember, every 10 dB difference means that loudness is increased or decreased by a factor of 10.  So 129 dB isn’t even a tenth as loud as a howler monkey.)  And the record for the loudest controlled human shout was set in 1994 by Belfast, Northern Ireland primary school teacher Annalisa Flanagan when she yelled the word “Quiet!” at 121.7 dB.  One assumes that both Ms. Drake and Ms. Flanagan drew upon their professions for inspiration.

     But my guy, Freddie, would need to be louder than an inspired primary-school teacher.  In fact, he would have to be even louder than a howler monkey, since I wanted him to be able, in extreme circumstances, to reach shock-wave territory.

     Okay, so, in the real world, how do you increase the loudness of a human voice far beyond its normal top shouting volume?

     Anyone who’s ever been to a rock and roll show knows the answer to that one.

     The way an electric guitar amplifier or vocal public address system works (well, sort of) is that you use a magnetic pickup or microphone to capture waves from strings or a voice, add electrical energy, and pump it all through a speaker.  And at that point, a much bigger sound comes out.  The more energy you put in, the louder the sound you’ll get . . . until you exceed the level that the amplifier’s fuses, circuits, or speakers can withstand.  At which point it will blow out.

     That was going to be Freddie.  He might have a throat similar to a howler monkey’s, but his body would behave like an amplifier driving a speaker.  

     For that metaphor to work – for me, anyway – Freddie would need to live a life that matched it, alongside people who could appreciate who he was and what he could do. So Freddie would be employed by a rock band.  But he couldn’t be inthe band.  Instead, he would have to be someone useful and even beloved, but ultimately expendable should he blow out.  

     In other words, he would be a rock’n’roll roadie.

     But a roadie employed by what band?

     For starters, it would have to be a really loud band.  I immediately thought of two great fictional examples:

     1. Spinal Tap, first seen in the film This Is Spinal Tap in 1984.  These guys were so good at pretending to be a real heavy metal band that I had friends who were convinced they were a real band, and that they had been performing as Spinal Tap since the 1960s.  Best of all, in the opening moments of the film,fictional director Marty DiBergi (played by actual director Rob Reiner) reverently explains that Spinal Tap has a well-deserved reputation as “one of England’s loudest bands.” 

     2. Disaster Area, described by Douglas Adams in his 1980 novel The Restaurant at the End of the Universe as being so loud that their music can devastate planets.  Brave audience members, though, will listen to the band’s concerts while tucked into a bunker thirty miles from the stage.  However, Disaster Area themselves, being more prudent, play their instruments by remote control while in orbit around an entirely different planet.    

     So, Option One:  I could make up a loud band.  

     But one of the best things about the world of Wild Cards, for a writer, is that it takes place in an alternate history.  The planet Earth of Wild Cards is our world, our Earth – it’s just an Earth where human history took a big left turn at Albuquerque in 1946.  

     Of course, not all of human history will make a big turn in perfect unison.  Not everything is completely changed.  This means that a lot of people – and rock bands – from the real world can still exist in the world of Wild Cards.  Yes, they’ve all been changed somehow.  But that change can be just about anything, as long as it’s not inconsistent with all the other changes that have resulted from the Wild Card virus.

     So I decided to have Freddie make his way through the world as a roadie for a real band.  Or, rather, for a band in the Wild Cards universe that had a real-world counterpart.  

     A really loud real band.

     Not surprisingly, a lot of rock bands in the real world have been measured playing at dangerous dB levels over the years.  Among many others, Kiss, Manowar, and Motörhead have all been measured at sound levels that can cause hearing loss.  Motörhead has even been accused of playing at levels that caused structural damage to a theater in Cleveland, dropping ceiling plaster onto the heads of their audience.  Heck, even Ax Nelson, a band I played drums for in the 1990s, performed only one outdoor gig (out of dozens over the years) during which the cops didn’t show up because of a noise complaint.  And this was despite the fact that our audience was always tucked into a bunker thirty miles away.

     But none of those bands would do for Freddie “Amplifier” Fullerton.  I didn’t want to use a band that was merely loud, since a lot of bands fit that description.  No, I wanted to use a band that was also critically praised, culturally iconic, and a Guinness Book World Record holder as “World’s Loudest Band.”

     That category has been discontinued for years, since the Guinness Book editors decided they didn’t want to reward deliberate ear destruction.  But in 1976, when I was eighteen (the same age as Freddie), the “loudest band” category was still in the Book.  And one four-member group reigned supreme.

     In London, England, on May 31, 1976, at a distance of 100 feet from the stage speakers at the Valley, the home of the Charlton Athletic Football Club, a rock concert reached a sustained sound pressure of 126 dB.  And the band responsible was . . . the Who. 

     That settled it.  Not only were the Who an officially loud band, but they were one of my favorite bands to boot.  Plus, in the Wild Cards universe, I could even resurrect the two band members who, in the real world, have long since gone to the great echo chamber in the sky.

     That’s why Freddie “Amplifier” Fullerton is a roadie for the Wild Cards universe’s version of the Who.  And it’s also why, on occasion, he even serves as one of their stage amplifiers.

     So, whether he’s an ace or not, Freddie is at least, as far as I’m concerned, the World’s Loudest Boy.  And he’s the proud culmination of a long, ear-splitting history of devastating noise produced by volcanoes, meteor explosions, earthquakes, hydrogen bombs, moon rockets, fighter planes, blue whales, howler monkeys, schoolteachers, and rock and roll bands.   

     Maybe even, when they were mad enough to use our full names – including our middle names – our moms.

     Thanks for listening!