2-Bits, 4-Bits, 6-Bits...
"People don't appreciate music any more. They don't adore it. They don't buy vinyl and just love it. They love their laptops like their best friend, but they don't love a record for its sound quality and its artwork."
Laura Marling, musician
2-Bits, 4-Bits, 6-Bits...We love convenience. Drive thrus, same-day delivery, automatic transmissions, instant coffee. Uh, maybe not that last one. Convenience often drives technology. And when it does, something has to go. What are you willing to give up for convenience? Taste, comfort, money, quality?
Convenience also influences new audio technology, and the result is portability, because we are a society on the go. So what did we give up to take Elvis along for the ride? In the early days of records, players got smaller and smaller so they could be moved from room-to-room, house-to-house, and even house-to-car. As the players got smaller, so did the sound. In the 1950's, engineers threw away the large vacuum tubes (and the warm sound) in radios for the minuscule transistor. Now you could hold Elvis in your hand. In the 60's, a wonderful little pocket-sized storage unit called the cassette tape came along that allowed you to take 2 or 3 records' worth of Elvis with you - but not the big sound.
And then came the iPod. Apple wasn't the first portable digital file player, but they made it a household name. Small device, small earbuds, small audio files - what's not to love? I admit that as a fan of convenience, I'm a huge fan of the iPod. The mp3 had been around for a while when the iPod came to town. This unique way of compressing large audio files down to smaller ones was created to speed up file transfers (remember, we were still using pokey dial-up modems at the time). So we sacrificed audio quality for speed.
At least Apple tried to address the loss-of-quality issue by authoring their own codec (code-decode algorithm). The AAC (Advanced Audio Coding) codec offers much better audio quality with even smaller file size, plus it does so much more than the mp3. If it's superior to an mp3, why isn't it more popular? Because Apple wants to sell Apple products. They usually keep a tight control on their technology, but have relaxed a little on AAC. You'll find it on Youtube, Nintendos, Playstations, Wiis, and many smartphones and car stereos. But it still isn't as popular as the venerable mp3. Sorta sounds like the old VHS - Betamax war doesn't it?
The reason for all the audio codec wars is to save time and space. Not something Arthur C. Clark would lay out in a textbook, but something of convenience - faster downloads and more tunes in your pocket. At ground zero in this war is the bit.
You generally win and get higher fidelity with more bits in a digital media signal. But convenience wins when you have fewer bits. Fewer bits, less time and space. The digital audio CD spits out 1.4 million bits per second of data (1,411 kbit/s). The highest quality mp3 produces 320 kbit/s - or 23% of what a CD does. Is the sound quality 23% less? It all depends upon your perception.
Mp3, AAC, Dolby AC3, and all the rest use perceptual coding technologies. Basically, what's really important gets less compression, and what isn't gets hit heavily or thrown out all together. Think of it as a stage play with real props on stage and a painted scenery backdrop. We trick the mind into thinking something faked is real. In audio codecs such as an mp3, the parts of the sound that take up the most file space (like the bass), are highly compressed. When playing them back, those parts are faked, just like that backdrop. A long time ago, someone in a computer lab decided how much bass you won't really hear.
When you stick that audio CD into your computer to make an mp3, you must make a few decisions that will affect the quality of your future entertainment. Do you want small size, or big sound? Choosing a small bit rate (like 64k, 96k, or even 128k) will reduce the file size considerably, but throw out a lot of those important stage props. Detail is lost. When it's played back, it may sound watery, jingly, or muffled - not quite the real thing. It's kind of like a sloppy paint-by-numbers scenery backdrop. But if you use a higher bit rate like 320 kbit/s, more detail is preserved. Better yet, use a modern codec like Apple's AAC to preserve even more.
Of course bit rate isn't the only deciding factor in audio quality, but it's the biggest. Consider this. A full-fledged cinematic motion picture is recorded and mixed at 96KHz, 24-bit, 7.1 surround - 18.4 million bits per second. An mp3 on your iPod is probably recorded at 128 thousand bits per second. That's less than seven-tenths of a percent of that movie sound. That's like Weird Al Yankovich vs. The Avengers. Bits will be flyin'!
Did You Know?The mp3 format is, unfortunately, a standard file format to send audio over the internet. Even with blazingly fast internet connections, many radio broadcast facilities still prefer commercials and programs to be sent in the mp3 format. Once these files are downloaded, they are often ingested into the station's audio file server, recompressing them into a new compressed format. This original audio file has been compressed twice at this point.
If the radio station's transmitter is at a remote location, the main audio signal is often digitally compressed over a transmission line from the studios to the transmitter site. The original audio has now been compressed three times.
If the radio station is transmitting a digital signal such as HD Radio or satellite, the original audio has now been compressed four times. If the original audio program or commercial contained any material that was in mp3 format, such as the voice-over or music, it has now been compressed five times.
This is a lot like playing "telephone" in grade school - but in different languages for each person. Each interpretation and retelling is dependent on who is hearing an retelling the story. A lot can be misinterpreted.
- The mp3 codec is formally called MPEG-2, Layer III (1995). It was first introduced in 1993 as MPEG-1, Layer III.
- The mp3 format was developed by the Fraunhofer Institute in Hanover, Germany. It is actually a brand and requires a paid license to include it in software or devices.
- The mp3, AAC, and AC3 use "lossy" compression, meaning audio information is "lost" when encoded.
- There are "lossless" codecs that successfully reduce file size but retain 100% of the audio information. Some of these codecs are Apple Lossless (ALAC), FLAC, ATRAC, HD-AAC, and WMA Lossless.
- Compression codecs take advantage of "perceptual" coding, first discovered in 1894 by American physicist Alfred M. Mayer . He discovered that a tone could be rendered inaudible by another tone of lower frequency.
- Small file size is the "pro" of an mp3. Decoding is the "con." It takes a lot more processing power to decode and play an mp3 than playing the original uncompressed audio format.
- Susan Vega's "Tom's Diner" was chosen as a benchmark during the development of the mp3. It is considered the "Mother of the mp3."
“There is a time for many words, and there is also a time for sleep.”
Homer, The Odyssey
If you've read The Odyssey or The Iliad, then you know why they've been literary classics for almost 3,000 years. But did you know they date to the earliest origins of the alphabet? It's believed that Homer's poems and speeches were so revered that early scribes dedicated themselves to writing them down. In fact, half of all Greek papyrus discoveries contain Homer's works. Homer must have been one cool dude to influence all of Western literature.
Now put on your time-travel caps and flash forward to the 1933. It's the early years of recording audio. Huddie Ledbetter was incarcerated in a prison in Louisiana when a father and son recording team came by. John and Alan Lomax were traveling the south on the dime of the Library of Congress to record and document African-American folk and blues musicians. John had found the LOC collections woefully inadequate and got funding to buy a "portable" (315 lbs.) disc recorder. There in the Angola Prison was the singer and 12-string guitar player better known as "Led Belly." Their collaboration over the next several years cemented Led Belly's place as a folk and blues legend.
Humans have long been documenting events with paintings on cave walls; sculptures; writing on papyrus; photographs; records and tapes; and film and video. One way we're doing it today is with oral histories. "Oral history" is a term used to describe recording someone relating personal experiences on audio or video. It's often used to supplement documents, pictures, artifacts, and visuals about an event or time period. Scholars say oral histories are a unique part of understanding history. Just hearing speech inflections and emotion in one's voice speaks volumes that printed text cannot.
Searching for key words in printed or digitized text is easy. Searching recordings can be extremely time consuming. In the past, recordings were done on disc or tape, so one had to listen to the whole recording. If they were lucky, a transcript existed. Recordings were usually only transcribed If funds, personnel, and time were available. But most recordings are in boxes collecting dust.
These days, oral histories are recorded digitally, an obvious quality advantage over analog. But the not-so-obvious advantage is search-ability. Doug Boyd of the Louis B. Nunn Center for Oral History at the University of Kentucky has developed a novel searchable method called OHMS (Oral History Metadata Synchronizer). Any content in the Nunn Center's online files can be searched using current speech recognition algorithms. It's not perfect, as Boyd points out, but it's a step in the right direction.
Anybody that's used Siri or Google voice search will understand that speech recognition is not perfect. OCR (Optical Character Recognition) was at this stage about a decade ago. Now, document scanners can scan, ingest, and convert paper text to a digital file in seconds with few errors. But the complexity of speech patterns, accents, and recording quality will demand more intricate software solutions. This will come, and oral history repositories will reap the benefits.
All this bleeding-edge technology like the alphabet and records lead me to wonder what the next thing is? Thought recording? Memory mining? Oh boy, now everyone will know I really wasn't that cool in high school. I was really a nerd. Oh wait, you already figured that out.
Did You Know?
Four generations of the Lomax family have contributed immensely to American music through recordings, archives, productions, management, and journalism.
- John Lomax grew up and Texas in the late 1800's and was influenced by cowboy folklore and songs.
- Some of John's professions were as an English professor, college administrator and banker.
- John co-founded the Texas Folklore Society, a chapter of the American Folklore Society.
- During his travels in the south recording folksongs during the 1930's, the entire Lomax family was heavily involved in the recording and research.
- Alan Lomax, John's son, continued his father's legacy of archiving folksongs. He was also a ethnomusicologist, writer, and filmmaker.
- Grandson John Lomax III is a music journalist and artist manager, having represented Townes Van Zandt and Steve Earle.
- Great-grandson John Nova Lomax is a music journalist and author.
- John Lomax's first field recordings were on wax cylinders. Fidelity was inferior to disc recordings, but disc recorders were not yet portable. Instead of a microphone, players performed into a bell or horn.
- John and Alan Lomax used some of the earliest disc recorders in the field. These were uncoated aluminum, in which the heavy vibrating needle would etch the surface. The discs were robust, but the grooves were shallow, and thus noisy.
- Alan started using lacquer-coated aluminum discs in the mid-30's. Fidelity was better, but the recording process was difficult. Spirals of shed lacquer and aluminum had to be continually brushed and blown away from the needle.
- Like the immediate feedback that digital cameras give us today, Lomax could immediately play the record back to the musician.
- These early disc recorders were so heavy that recordists often installed them in the back of old ambulances. They required alternating current (AC), so Lomax often used his car battery in conjunction with a portable transformer to power the recorder.
Star Wars With One Major Piece Missing
"I don't appreciate avant-garde, electronic music. It makes me feel quite ill."
When you think of electronic music, you often think of the straightforward synthesizer, electric piano, or loops and samples. But some musicians like to rewire, alter, or downright reconstruct electronic equipment to make sounds they weren’t originally intended to do. At the forefront of these experimentations was BBC’s Radiophonic Workshop, a special music lab that gave us unique sounds and music for hit TV shows such as Dr. Who.
A Sound Education
“Education is the kindling of a flame, not the filling of a vessel.”
What young person really knows what they want to be when they grow up? Very few of my childhood friends are still on the path they laid out early in life. Most of us have zig-zagged through careers, including me. Unlike today, if you wanted to be an audio engineer in the 70's like I did, there were very limited educational opportunities. Most recording engineers started as musicians or disc jockeys and fell into the job. As a teenager in the late 70's, I was into music more than anything. I hung out in radio and TV stations and got my first exposure to a "real" recording studio in a friend's basement. I was a child of tape. In fact, as a child I ran around my house with a cassette recorder taping anything that I found interesting. I would often shove a microphone into the face of a shy family member, who would naturally be at a loss for words. But when a teen nears graduation, the pressure builds into making that big life decision - "what will I grow up and be?"
3D Sound on the Right Track
“Even if you're on the right track, you'll get run over if you just sit there.”
3D Audio on the Right Track
It's said that when an early motion picture was first shown to the public, women fainted and men ducked from an approaching train. The director made a bold new decision that would alter the course of filmmaking for the next century. Instead of just placing the camera in front of all the action like an audience watching a stage, the director moved the camera to a new position - within the action - to create perspective. There were more changes on the way. About a hundred years ago, the first color and 3D films were being created. In an Avant Garde era when artists were distorting reality, most filmmakers were trying to recreate reality and immerse the viewers into it.
Realistic sound is no exception. In fact, stereo sound was first demonstrated in 1881, and multiple speaker playback in the early 1930's. These early attempts at locating sounds for the listener were impractical though, and required expensive and ungainly equipment. By the late 1950's, consumers could finally experience stereo with LPs and tapes. But until home theater systems became popular, most had to go to a place like a theater or theme park to experience anything beyond stereo sound.
Since digital audio and video have pretty much taken over the world, we've seen a rapid growth of new technologies. Virtual reality is one of those, like the Oculus Rift, a VR headset for the masses. This is a visual VR device. But what's lacking is auditory VR.
Enter the researchers at Microsoft. They've created a way to fool a listener into thinking sounds are coming from a specific location using ordinary headphones. To make it work, the listener's head and shoulders are scanned into 3D software, which then builds a custom filter. Add motion sensors and a camera to track the listener's position, and the fun begins. Sounds can seem to be coming from objects or areas in a room. Imagine making that stuffed Teddy bear in the corner of your child's room actually talk. That model hot rod on the shelf could rev its engine. The uses seem endless.
It's obvious that this new device will be used as a companion to a visual VR headset. But there could be many more uses. Theme park attractions could be revolutionized by creating more realistic environments while eliminating costly sound systems. The movie industry could enhance the viewer's experience. Music artists could create the ultimate mix, with that lead guitarist standing next to the coffee table.
I think the largest user of this technology will be the advertising industry. Imagine walking down the street with your headphones listening to some music when a voice from your left whispers, "Pssst! Hey buddy, wanna buy a watch?" You turn and see the sparkling Bulova timepiece in the window of the jewelry store.
Train photo courtesy Simon Pielow
Did You Know?
- In Paris in 1881, Clément Ader demonstrated the first two-channel sound utilizing telephone transmitters. As part of an exhibition, the Paris Opera performances were heard at a remote location by listeners wearing headphones. Scientific American immediately picked up on the aural spaciousness compared to a single receiver.
- Adre's process was later marketed in France for over 40 years as the Théâtrophone. These coin-operated devices were popular in hotels, cafés, and clubs. There were also many homes that had the Théâtrophone by subscription.
- Similar services were the Electrophone in England and the Telefon Hírmondó in Budapest. In the U.S., there were only one-time experiments.
- The Théâtrophone service also included short news readings, making it a prototype to the telephone newspaper as well as the first example of electronic broadcasting.
- The popularity of radio and the phonograph killed the Théâtrophone by 1932.
One of the fundamentals of recording and mixing is deciding what kind of spatial experience the listener will have. Creating a realistic one is difficult. If accuracy is not adhered to strictly, the result is a false space. An example of a near realistic auditory recording and playback is to place two microphones closely together in front of a performance. During playback, the listener is positioned in front of two loudspeakers at about the same angle and distance as the microphone were placed. This is a fairly pleasing experience, but isn't 100% accurate because everyone's playback system and environment is different.
A false spatial method is called "pan-pot" stereo. Mono or stereo tracks are "panned" in the mix away from center. An example might be a cowbell panned slightly to one side ('More cowbell!"). Most contemporary pop and rock songs are constructed this way because the tracks were built one performer at a time.
Recording engineer and producer Bruce Swedien (who recorded and mixed the biggest-selling album of all time, Michael Jackson's Thriller) likes to pre-plan his stereo mix. If Swedien wanted that cowbell on the left side of the mix, he would record it in stereo with the performer standing to the left. In the analog tape days this required careful planning because engineers were limited to a finite number of tracks. Most recorders had 16 or 24 tracks. If all instruments are recorded separately in stereo, then that limited the tracks to 8 or 12.
Most stereo recordings are intended to be heard on speakers. Once the listener uses headphones, the aural space changes dramatically. Instead of left and right sounds coming from forward of the listener (from the speakers), they are now coming from extreme left or right. Anything that was intended for the front middle (like the vocalist or lead guitar), is now coming from inside the head, right in the middle. It's a hyper-real experience, and immediately going back to front speakers elicits a lifeless experience.
There is one recording technique that requires listening only on headphones. This ultimate 2-channel spatial experience is called binaural recording. Two microphones are placed either in a mannequin head with false ears, or over the recordist's ears. Whatever the recordist hears is correctly translated to the listener. A common use for binaural recordings is an audio tour. How about a walk through Chinatown on a busy Monday morning? Or a walk through a submarine as she makes her dive to 300 feet. The listener is instantly transported to the locale.
I did this on a project that required me to be in a crowd at a sporting event. I wore headphones that had small microphones (lavalieres) clipped on the outside. To the unsuspecting person, I was just someone listening to some beats. To the listener, I was their portal to the game.
Some resources to listen to binaural recordings (be sure to use your headphones):
A studio music performance from the videographer's perspective
Binaural mixes on Sound Cloud
Sounds of Bach
Learn more about binaural recording
Get in the Groove!
The new generation is discovering what the old generation stopped loving - LPs. LP sales are the highs they’ve been in 22 years. Records aren’t just for hipsters anymore, everyone, including the older generation that gave them up, are groovin’ to them.Read More...
The Color of Sound
“Within You Without You,” The Beatles
How would you describe a sound to someone without using descriptors that are unique to sound, like: loud, bassy, shrill, whining, atonal, or noisy?
Not a problem, because we most often describe a sonic experience with words related to our other senses: sharp, warm, angular, raspy, piercing, even, warbling, soft, smooth, or flat.
Aaron Copland, 1970
WIth the recent news that the Library of Congress is inducting 25 entries into the Library of Congress National Recording Registry, I was excited to see U2, Linda Ronstadt, and Isaac Hayes get their due. Perusing the list, I saw a very influential (at least personally) album - Copland Conducts Copland: Appalachian Spring (1974).
I was a music major in college and always found Aaron Copland to be the quintessential American composer. He seemed to capture what Americans idolize about America: hope, boldness, charm, intrepidness, looking forward but not forgetting the past.
The BIrth of Recording
The Birth of Recording
Dreamers in the 19th century seemed to be driven by the need to capture things. Animals were captured and put into the first American zoos In Philadelphia, Chicago, Cincinnati, and New York. Light was captured by Joseph Niépce and Louis Daguerre in France. And sound was captured in France by Édouard-Léon Scott de Martinville. Scott? De Martin--who? I always thought Thomas Edison had been the first. Read More...
When Recording Writes the Music
When commercial radio really took off in the 1920's and 30's, it was fueled by advances in recording. You could even say that each drove the other. Early music recordings were mostly documents of what was already being played to live audiences - classical, early jazz, folk, etc. As bands got bigger and louder, the music got more exciting. Dixieland was new, records were all the rage, and radio was just beginning to transport the new sounds across the country, just like the transcontinental railway brought the ideas of the gilded age to America a half-century earlier.
How Things Work
Inside an Engineer's Mind
- Thomas Edison
- Alan Parson
- Am radio
- Am Radio
- Amateur radio
- Amy Winehouse
- Angels on Stage
- Artificial intelligence
- ATR Magnetics
- Audio engineer
- Bela Lugosi
- Bell Labs
- Big Bang
- Book on tape
- Brown noise
- Carrier pigeon
- CB Radio
- Civil War
- Dies irae
- dorian mode
- Dynamix Productions
- ear training
- Film Sound
- Fleetwood Mac
- Fritz Lang
- George Clooney
- Guinness World Record
- Hearing aid
- Jack White
- John Mellancamp
- John Williams
- Ken Burns
- Led Belly
- Led Zepelin
- Lenny Kravitz
- Les Paul
- Mary Ford
- Morse code
- mykola Leontovych
- Noise Pollution
- Noise reduction
- Oculus Rift
- Peter J. Wilhousky
- Pink noise
- Ray Bradbury
- Recording arts
- Recording school
- Reel to reel
- Richard Wagner
- Rudy Van Gelder
- Rupp Arena
- Secret messages
- Silent film
- Sir Isaac Newton
- Smokey and the Bandit
- sony walkman
- sound effects
- sound level
- sound pressure level
- sound wave
- Star Wars
- surround sound
- Taylor Swift
- The Beatles
- Thomas Edison
- Time travel
- US Navy
- virtual reality
- Wax cylinder
- White noise