Podcast

Podcasting is a way of publishing sound files to the Internet, allowing users to subscribe to a feed and receive new audio files automatically. Podcasting is distinct from other types of audio content delivery because it uses the RSS 2.0 protocol. This technique has enabled many producers to create self-published, syndicated radio shows.

Users subscribe to podcasts using "podcatching" software (also called "aggregator" software) which periodically checks for and downloads new content. It can then sync the content to the user's portable music player, hence the portmanteau of Apple's "iPod" and "broadcasting". Podcasting does not require an iPod; any digital audio player or computer with the appropriate software can play podcasts.

By 2003, a number of blogs already published audio online, and the RSS protocol was widely used for summarizing or syndicating content. Using RSS, former NPR host Christopher Lydon attached audio files to his weblog. Lydon's full-length interviews, which focused on blogging and coverage of the 2004 U.S. presidental campaigns, helped to inspire Adam Curry's iPodder script. Indeed, blogs would become an important factor in the popularization of podcasting.

Origin of the word

One of the first uses of the term "podcasting" was in an article in The Guardian [1] on February 12, 2004, though it didn't detail the RSS protocol or automatic synchronization. In September of that year, Dannie Gregoire used the term to describe the automatic download and synchronization idea that Adam Curry had developed. Gregoire had also registered multiple domain names associated with podcasting. That usage was discovered and reported on by Curry and Dave Slusher of the Evil Genius Chronicles website. The term "podcatcher" was coined by Doug Kaye, creator of IT Conversations....

Unique attributes

Differences from traditional broadcasting

Unlike radio or streaming media, podcasts are time-shifted, meaning that listeners have control over when they hear the recording. This has disadvantages, since podcasts cannot have live participation or reach large audiences as quickly as radio can.

However, podcasting has significant advantages over traditional methods of broadcasting due to the egalitarian nature of the technique. In most countries, the radio spectrum is heavily regulated, and personal broadcast licenses are difficult or impossible to obtain. Podcasting allows individuals to easily transmit content worldwide without these difficulties.

Differences from other forms of online audio

Podcasting differs from broadcasting and webcasting in the way that content is transmitted. Instead of a central audio stream, listeners download audio files remotely and automatically. Podcasts can also include metadata such as dates, titles, and descriptions. Podcasting differs from autocasting in terms of content; podcasts are generally voice broadcasts while autocasting is a speech-synthesized version of regular text blogs. Audioblogs can be easily made into podcasts if they add support for RSS to facilitate automatic retrieval.

Radio stations

Beginning in late 2004, some radio stations began to find podcasting suited to their style of programming. Some examples:

• In Canada, CBC Radio One is experimenting with the format on at least one regular radio show, Quirks and Quarks, and it is also planned for CBC Radio Three programming. Corus Entertainment radio stations across Canada are also providing podcasts for specialty shows.

• In Australia, the ABC's Radio National and Triple J Networks are making a number of programs - including current affairs, science and live music - available for downloading at ABC's Radio National Audio Downloads page and Triple J Podcasts page. Cyber Shack offers each week's show on their Cyber Shack podcast page

• In Spain, the private radio station Cadena Ser has also started to podcast most of its programs, including a Spanish manual on its website

• In the UK, the BBC has launched download and podcasting trial, including the Saturday-morning sports-punditry radio game show Fighting Talk, and the flagship Radio 4 Today Programme.

• In the U.S., on October 4, 2004, Leo Laporte began re-broadcasting his KFI Los Angeles radio show as a podcast feed, apparently one of the first to do so. Numerous public, non-profit and college stations have followed suit.

• In San Francisco as of May 15, 2005, a poorly performing Infinity Broadcasting-owned radio station, KYOURadio, is broadcasting podcasts made by listeners. Adam Curry will host a four-hour program radio program on Sirius Satellite Radio that will discuss and air podcasts.

• Rush Limbaugh recently announced that his daily show will be available to Rush-24 members as a podcast beging June 3rd.

External links

• What is Podcasting? at iPodder.org
• Podcasting Related Articles at podcasting-tools.com
• Podcasting VODcasting whitepaper at apple.com (PDF file)
• Podcasting For Dummies at digitalmusicmuseum.com
• Educational Podcasting Articles and tips and tricks for educators interested in the use of podcasting.