Audio Formats
Forms of recorded audio have made many developments over recent history. To explore different audio formats in our collection, visit UT Special Collections & Archives in Holland 330 or check out the Digital Collections: https://digital.library.utahtech.edu/
Reels
Magnetic tape reels were first invented by German engineers in the 1930s.[1] To record audio, sound waves are converted into an electrical signal which is then applied to the tape using a process called magnetization, where a magnetic imprint is left on the tape by a tape head.[2] Tape heads are transducers that can read, write, and erase magnetization on the tape using the magnetic particles.
To play back the recorded audio, a reel-to-reel machine is used to transfer the tape from the supply reel to the takeup reel. As the tape is moved from one reel to another, it moves over the tape head which converts the magnetized signal back to an electrical signal which is then sent to the amplifier and speakers.
The most common speeds for consumer tapes are 3¾ ips (inches per second) and 7½ ips; 30 ips and 15 ips were most commonly used for professional recordings.[3] Most reels in our collection are played at either 3¾ or 7½ ips.
Cassette tapes
Cassette tapes were first introduced in 1963 when the Dutch company Philips released its first compact cassette tape.[4] Compared to reel-to-reel format, cassette tapes were much smaller and more convenient. The commercial popularity of cassette tapes grew in 1979 when Sony released the Walkman, a portable audio player.[5]
Similar to open reels, cassette tapes use magnetic tape for audio recording and playback. The tape feeds from one reel to the other inside a cartridge case. Cassettes can have two or four tracks by recording on both sides of the tape.[6] To play both sides of the tape, the tape is either manually flipped or automatically reversed.
CDs
The CD, or compact disc, was first developed in 1976 by Phillips and Sony. CDs can hold up to 700 megabytes or 80 minutes of uncompressed audio.[7] In 1982, CD players and CDs entered the market,[8] and by 1985 an album sold more on compact disc than on vinyl for the first time.[9]
Audio is recorded on a CD by etching into a disc with a laser. This creates bumps which are read in a continuous spiral outwards from the disc’s center using a CD player or other disc reader.[10]
.mp3 files
MP3 is a file format for digital audio. MP3 first became a reality in 1992,[11] but only became wide-spread to consumers in 1999 with the advent of the file-sharing app Napster and in 2001 with the release of the Apple iPod.[12]
MP3 files are compressed to a smaller size than other files, making them easier to share and store.[13] Visit our Digital Collections to view digitized interviews and oral histories in the form of MP3s: https://digital.library.utahtech.edu/oral-histories
Over time, audio formats have grown to improve playback quality and to be more convenient and accessible for users. Now, more than ever, anyone can create and share audio records through social media with audio production apps and AI. Popular sites such as Spotify and TikTok play a major role in today’s audio scene, with an average 103,500 tracks uploaded to streaming services daily in 2023.[14] Podcasts have also swiftly gained popularity, reaching 546 million listeners around the world in 2024 on platforms including YouTube, Spotify, and Apple Podcasts.[15] By interacting with and creating your own audio records such as music, podcasts, and interviews, you can also contribute to the historical record and future archival materials. Learn more about how you affect the future in the archives by visiting UT Special Collections & Archives in Holland Centennial Commons & Library 330 or contacting us at speccoll@utahtech.edu.
References
[1]Marshall Brain, “How Tape Recorders Work,” HowStuffWorks, April 1, 2000, https://electronics.howstuffworks.com/gadgets/audio-music/cassette.htm.
[2]Ascagne van de Laar, “How Reel-to-Reel Tape Recorders Work,” Retro Reels : Premium Analog Audio, 2024, https://www.retroreels.shop/how-reel-to-reel-tape-recorders-work/.
[3]Dave Denyer, “Tape Formats,” Dave Denyer: The Reel-to-Reel Rambler, July 22, 2021, https://thereeltoreelrambler.com/reel-to-reel-tape-a-beginners-guide/tape-formats/#:~:text=Like%20vinyl%20records%2C%20open%20reel%20tapes%20can%20be,faster%20the%20speed%2C%20the%20better%20the%20reproduction%20quality.
[4]“First Philips Cassette Recorder, 1963,” Philips, January 1, 2019, https://www.philips.com/a-w/about/news/media-library/20190101-First-Philips-cassette-recorder-1963.html.
[5]“Personal Audio,” Sony Group Portal - Product & Technology milestones, accessed September 23, 2024, https://www.sony.com/en/SonyInfo/CorporateInfo/History/sonyhistory-e.html.
[6]“Compact Cassette (1963 – ),” Museum of Obsolete Media, May 3, 2024, https://obsoletemedia.org/compact-cassette/.
[7]Jeremy Norman, “The Compact Disc (CD) Is Developed,” HistoryofInformation.com, July 15, 2024, https://historyofinformation.com/detail.php?entryid=1189#:~:text=Visitors%20by%20ABBA-,.
[8]Hans B. Peek, “The Emergence of the Compact Disc,” IEEE Communications Magazine 48, no. 1 (January 2010): 10–17, https://doi.org/10.1109/mcom.2010.5394021.
[9]Dorian Lynskey, “How the Compact Disc Lost Its Shine,” The Guardian, May 28, 2015, https://www.theguardian.com/music/2015/may/28/how-the-compact-disc-lost-its-shine.
[10]Marshall Brain, “When Were Cds Invented, and How Do They Work?,” HowStuffWorks, April 1, 2000, https://electronics.howstuffworks.com/cd.htm.
[11]Joel Rose and Jacob Ganz, “The MP3: A History of Innovation and Betrayal,” NPR, March 23, 2011, https://www.npr.org/sections/therecord/2011/03/23/134622940/the-mp3-a-history-of-innovation-and-betrayal.
[12]Brett Milano, “The Digital Music Revolution: From the MP3 to Music-IS-Free,” udiscovermusic., October 22, 2023, https://www.udiscovermusic.com/stories/digital-music-revolution/.
[13]Marshall, Brain. “How MP3 Files Work.” HowStuffWorks, April 1, 2000, https://computer.howstuffworks.com/mp3.htm.
[14]David Salazar, “5 Numbers That Will Define the Music Industry in 2024,” Fast Company, January 14, 2024, https://www.fastcompany.com/91009342/fix-numbers-that-will-define-the-music-industry-2024.
[15]Backlinko Team, “Podcast Statistics You Need to Know in 2024,” Backlinko, September 16, 2024, https://backlinko.com/podcast-stats.