| The evolution of electronic personal music media | | | | algorithm that is designed to greatly reduce the |
| extends back to the development of the phonograph | | | | amount of data required to represent the audio |
| in the mid 1800’s and is still metamorphosing into | | | | recording, yet still sound like a faithful reproduction of |
| the 21st century. I would like to give a little history | | | | the original uncompressed audio to most listeners. It |
| lesson on this progression. Phonograph Record The | | | | was invented by a team of European engineers. MP3 |
| original author of the word phonograph was F.B. | | | | is an audio-specific format. The compression takes |
| Fenby an inventor in Worcester, Massachusetts; he | | | | off certain sounds that cannot be heard by the |
| was granted a patent in 1863 for an unsuccessful | | | | listener, i.e. outside the normal human hearing range. It |
| device called the “Electro-Magnetic | | | | provides a representation of pulse-code modulation |
| Phonograph”. His concept detailed a system that | | | | encoded audio in much less space than |
| would record a sequence of keyboard strokes onto | | | | straightforward methods, by using psychoacoustic |
| paper tape. Although no model or workable device | | | | models to discard components less audible to human |
| was ever made, it is often seen as a link to the | | | | hearing, and recording the remaining information in an |
| concept of punched paper for player piano rolls. | | | | efficient manner. Similar principles are used by JPEG, |
| Arguably, any device used to record sound or | | | | an image compression format. Modern lossy bit |
| reproduce recorded sound could be called a type of | | | | compression technologies, including MPEG, MP3, etc, |
| "phonograph", but in common practice it has come to | | | | are based on the early work of Prof Oscar Bonello of |
| mean historic technologies of sound recording. In the | | | | the University of Buenos Aires, Argentina. He was |
| late 19th and early 20th century, the alternative term | | | | involved in Studio equipment design for Broadcast |
| talking machine was sometimes used. The | | | | radio automation. At the same time he taught |
| phonograph, or gramophone, was the most common | | | | Acoustics at the University, Psychoacoustics being his |
| device for playing recorded sound from the 1870s | | | | main field of research. In 1983 he started researching |
| through the 1980s. Usage of these terms is not | | | | the idea of using the Critical Band Masking principle (a |
| uniform across the English-speaking world. In more | | | | property of the ear) in order to reduce the bit |
| modern usage, this device is often called a turntable, | | | | stream needed to encode an audio signal. The |
| record player, or record changer. The phonograph | | | | masking principle was discovered in 1924 and further |
| was the first device for recording and replaying | | | | developed by in 1959. Bonello's work created, in 1987, |
| sound A gramophone record (also phonograph | | | | the world's first bit compression system, named |
| record, or simply record) is an analogue sound | | | | ECAM, working in real time and implemented by |
| recording medium consisting of a flat disc with an | | | | hardware on an IBM PC computer. This plug in card |
| inscribed modulated spiral groove starting near the | | | | and the associated control software was |
| periphery and ending near the center of the disc. | | | | demonstrated for the first time in 1988 as a fully |
| Gramophone records were the primary medium used | | | | working product named Audicom and introduced to |
| for commercial music reproduction for most of the | | | | the world at the international NAB Radio Exhibition in |
| 20th century. They replaced the phonograph cylinder | | | | Atlanta, USA on 1990. The basic Bonello |
| as the most popular recording medium in the 1900s, | | | | implementation is now used in MP3 and other |
| and although they were supplanted in popularity in | | | | systems. Bonello refuses to apply for any patents |
| the late 1980s by digital media, they continue to be | | | | around this technology. A reference simulation |
| manufactured and sold as of 2007 The terms LP | | | | software implementation, written in the C language |
| record (LP, 33, or 33-1/3 rpm record), EP, 16-2/3 rpm | | | | and known as ISO 11172-5, was developed by the |
| record (16), 45 rpm record (45), and 78 rpm record | | | | members of the ISO MPEG Audio committee in order |
| (78) each refer to specific types of gramophone | | | | to produce bit compliant MPEG Audio files (Layer 1, |
| records. Except for the LP and EP (which are | | | | Layer 2, Layer 3). Working in non-real time on a |
| acronyms of Long Play and Extended Play | | | | number of operating systems, it was able to |
| respectively), these type designations refer to their | | | | demonstrate the first real time hardware decoding |
| rotational speeds in revolutions per minute (RPM). LPs, | | | | (DSP based) of compressed audio. Some other real |
| 45s, and 16s are usually made of polyvinyl chloride | | | | time implementation of MPEG Audio encoders were |
| (PVC), and hence may be referred to as vinyl | | | | available for the purpose of digital broadcasting (radio |
| records or simply vinyl. Tapes The Compact | | | | DAB, television DVB) towards consumer receivers |
| Cassette, often referred to as audio cassette, | | | | and set top boxes. Later, on July 7, 1994 the |
| cassette tape, cassette, or simply tape, is a magnetic | | | | Fraunhofer Society released the first software MP3 |
| tape sound recording format. Although it was | | | | encoder called l3enc. The filename extension .mp3 |
| originally intended as a medium for dictation, | | | | was chosen by the Fraunhofer team on July 14, 1995 |
| improvements in fidelity led the Compact Cassette to | | | | (previously, the files had been named .bit). With the |
| supplant reel-to-reel tape recording in most | | | | first real-time software MP3 player Winplay3 |
| non-professional applications. Its uses ranged from | | | | (released September 9, 1995) many people were able |
| portable audio to home recording to data storage for | | | | to encode and playback MP3 files on their PCs. |
| early microcomputers. Between the 1960s and early | | | | Because of the relatively small hard drives back in |
| 2000s, the cassette was one of the three most | | | | that time (500 MB) the technology was essential to |
| common formats for prerecorded music, alongside | | | | store non-instrument based music for listening on a |
| the LP and later the Compact Disc. The word | | | | computer. In October 1993, MP2 (MPEG-1 Audio |
| cassette is a French word meaning "little box." | | | | Layer 2) files appeared on the Internet and were |
| Compact Cassettes consist of two miniature spools, | | | | often played back using the Xing MPEG Audio Player, |
| between which a magnetic tape is passed and | | | | and later in a program for Unix by Tobias Bading |
| wound. These spools and their attendant parts are | | | | called MAPlay, which was initially released on February |
| held inside a protective plastic shell. Two stereo pairs | | | | 22, 1994 (MAPlay was also ported to Microsoft |
| of tracks (four total) or two monaural audio tracks | | | | Windows). Initially the only encoder available for MP2 |
| are available on the tape; one stereo pair or one | | | | production was the Xing Encoder, accompanied by |
| monophonic track is played or recorded when the | | | | the program cdda2wav, a CD ripper used for |
| tape is moving in one direction and the second pair | | | | extracting CD audio tracks to Waveform Audio Files. |
| when moving in the other direction. This reversal is | | | | The Internet Underground Music Archive (IUMA) is |
| achieved either by manually flipping the cassette or | | | | generally recognized as the start of the on-line music |
| by having the machine itself change the direction of | | | | revolution. IUMA was the Internet's first high-fidelity |
| tape movement ("auto-reverse"). Stereo 8, | | | | music web site, hosting thousands of authorized MP2 |
| commonly known as the 8-track cartridge, is a | | | | recordings before MP3 or the web was popularized. |
| magnetic tape technology for audio storage, popular | | | | In the first half of 1995 through the late 1990s, MP3 |
| from the mid-1960s to the early 1980s. Stereo 8 was | | | | files began to spread on the Internet. MP3's |
| created by a consortium led by Bill Lear in 1964 of | | | | popularity began to rise rapidly with the advent of |
| the Lear Jet Corporation, along with Ampex, Ford, | | | | Nullsoft's audio player Winamp (released in 1997), the |
| Motorola, and RCA Records. It followed the similar | | | | UNIX audio player mpg123 and the peer-to-peer file |
| Stereo-Pak 4-track cartridge. A later quadraphonic | | | | sharing network Napster (released in 1999). These |
| version of the format was known as Quad 8 or Q8. | | | | programs made it simple for average users to play |
| The original format for magnetic tape sound | | | | back, create, share and collect MP3s. The small size |
| reproduction was reel-to-reel audio tape recording, | | | | of MP3 files has enabled widespread peer-to-peer file |
| first made widely available after World War II in the | | | | sharing of music, which would previously have been |
| late 1940s. However, threading tape into the | | | | near impossible. The major record companies, who |
| recorders was more difficult than simply putting a | | | | argue that such free sharing of music reduces sales, |
| disc record onto a phonograph player. Manufacturers | | | | reacted to this by pursuing law-suits against Napster, |
| introduced a succession of cartridges which held the | | | | which was eventually closed down, and eventually |
| tape inside a metal or plastic housing to eliminate | | | | against individual users who engaged in file sharing. |
| handling. The first was RCA Victor, which in 1958 | | | | Despite the popularity of MP3, online music retailers |
| introduced a cartridge system, but until the | | | | often use other proprietary formats that are |
| introduction of the Compact Cassette in 1963 and | | | | encrypted (known as Digital Rights Management) to |
| Stereo 8 in 1964, none was very successful. | | | | prevent users from using purchased music in ways |
| Compact Disc A Compact Disc or CD is an optical | | | | not specifically authorized by the record companies. |
| disc used to store digital data, originally developed for | | | | The record companies argue that this is necessary to |
| storing digital audio. The CD, available on the market | | | | prevent the files from being made available on |
| in late 1982, remains the standard physical medium | | | | peer-to-peer file sharing networks. However, this has |
| for commercial audio recordings as of 2007. An audio | | | | other side effects such as preventing users from |
| CD consists of one or more stereo tracks stored | | | | playing back their purchased music on different types |
| using 16-bit PCM coding at a sampling rate of 44.1 | | | | of devices. Some services, such as eMusic, continue |
| kHz. Standard CDs have a diameter of 120 mm and | | | | to offer the MP3 format, which allows users to |
| can hold approximately 80 minutes of audio. There | | | | playback their music on virtually any device. When |
| are also 80 mm discs, sometimes used for CD | | | | creating an MP3 file, there is a trade-off between the |
| singles, which hold approximately 20 minutes of audio. | | | | amount of space used and the sound quality of the |
| Compact Disc technology was later adapted for use | | | | result. Typically, the creator of the MP3 file is allowed |
| as a data storage device, known as a CD-ROM, and | | | | to set a bit rate, which specifies how many kilobits |
| to include record-once and re-writable media (CD-R | | | | the file may use per second of audio, for example, |
| and CD-RW respectively). CD-ROMs and CD-Rs | | | | when ripping a compact disc to this format. The |
| remain widely used technologies in the Computer | | | | lower the bit rate used, the lower the audio quality |
| industry as of 2007. The CD and its extensions have | | | | will be, but the smaller the file size. Likewise, the |
| been extremely successful: in 2004, the annual | | | | higher the bit rate used, the higher quality, and |
| worldwide sales of CD-Audio, CD-ROM, and CD-R | | | | therefore, larger the file size the resulting MP3 will be. |
| reached about 30 billion discs. The Compact Disc | | | | As described, MP3 files encoded with a lower bit rate |
| reached the market in late 1982 in Asia, and early the | | | | will generally play back at a lower quality. With too |
| following year in the United States and other | | | | low a bit rate, "compression artifacts" (i.e., sounds |
| markets. The first CDs available were 16 | | | | that were not present in the original recording) may |
| Japanese-made titles from CBS/Sony. This event is | | | | be audible in the reproduction. Some audio is hard to |
| often seen as the "Big Bang" of the digital audio | | | | compress because of its randomness and sharp |
| revolution. The new audio disc was enthusiastically | | | | attacks. When this type of audio is compressed, |
| received, especially in the early-adopting classical | | | | artifacts such as ringing or pre-echo are usually heard. |
| music and audiophile communities and its handling | | | | A sample of applause compressed with a relatively |
| quality received particular praise. As the price of | | | | nominal bit rate provides a good example of |
| players sank rapidly, the CD began to gain popularity | | | | compression artifacts. Besides the bit rate of an |
| in the larger popular and rock music markets. The CD | | | | encoded piece of audio, the quality of MP3 files also |
| was originally thought of as an evolution of the | | | | depends on the quality of the encoder itself, and the |
| gramophone record, rather than primarily as a data | | | | difficulty of the signal being encoded. As the MP3 |
| storage medium. Only later did the concept of an | | | | standard allows quite a bit of freedom with encoding |
| 'audio file' arise, and the generalizing of this to any | | | | algorithms, different encoders may feature quite |
| data file. From its origins as a music format, Compact | | | | different quality, even when targeting similar bit rates. |
| Disc has grown to encompass other applications. In | | | | Quality is heavily dependent on the choice of encoder |
| June 1985, the CD-ROM (read-only memory) and, in | | | | and encoding parameters. While quality around |
| 1990, CD-Recordable was introduced, also developed | | | | 128kbps was somewhere between annoying and |
| by Sony and Philips. While CDs are significantly more | | | | acceptable with older encoders, modern MP3 |
| durable than earlier audio formats, they are | | | | encoders can provide very good quality at those bit |
| susceptible to damage from daily usage and | | | | rates. The advances in this technology is exploding as |
| environmental factors. MP3 MPEG-1 Audio Layer 3, | | | | is the quality of the devices, will our grandchildren be |
| more commonly referred to as MP3, is a popular | | | | as shocked at our current media as we are with our |
| audio encoding format. It uses a loosy compression | | | | grandparents? |