Podcasting Technology: What is it?

Podcasting is a form of audio distribution that can be either live or pre-recorded. As the name "podcast" implies, it is distributed as an audio download over the Internet using RSS feeds, downloads or streaming. Podcasts are also called webcasts and can consist of radio-like programming, including music, news or talk radio. The term podcasting usually refers to the downloading and listening to of these files on a mobile device such as an iPod or personal digital assistant (PDA).

Unlike commercial broadcasting which relies on advertising revenue from sponsorships to generate income for content providers and distributors, podcasting relies exclusively on subscriptions from users who want access to more content in exchange for a small monthly fee. As such, the content providers and distributors of podcasts are known as podcasters.

Podcasting can be done for personal or professional reasons, such as a hobby or as a means to market a business. The word podcast is the common term used to describe both live and pre-recorded audio programs that are distributed over the Internet using RSS feeds, downloadable files or streaming audio. Podcasts can be broadcast over the Internet from a computer directly into a computer's sound card (therefore requiring little to no additional hardware), through online streaming from an internet radio station (such as those featured on iTunes), or by downloading an MP3 file and playing it through any number of various portable media players.

Podcasting is most often facilitated by a computer, as the term implies. Podcast listeners can listen to podcasts either through a dedicated audio podcast program or through an aggregator that supports podcasts. A podcast aggregator, also called a podcatcher, webcaster or feed reader, is a computer application that can subscribe to hundreds of different audio programs (i.e. podcasts) and download them once per week or daily into the user's computer for listening later. There are additionally some dedicated hardware devices available (often portable) that are designed for the same purpose.

Podcasts may be recorded at a variety of speeds and file sizes, depending on the intended use of the podcast. For example, an audio podcast for general purposes may be recorded at a slower speed than one designed for mobile devices or low-bandwidth connections. Some audio podcasts can be recorded in a single take, whereas others will be edited and spliced together from multiple takes or recordings. Some podcasts may include visual elements such as images or video clips.

Audio podcasting is usually accomplished through the use of a USB microphone attached to the host computer, an analog telephone modem, digital subscriber line (DSL) or an Internet service provider (ISP) that supports Voice over Internet Protocol (VoIP). A computer can act as both a recorder and distributor of podcasts. Some, or even most, podcasters use this method as a way to "streamline" their work, because it eliminates the need for an additional piece of equipment.

However, there are drawbacks to this method. First, the computer does not know how loud a given sound is when recorded from the computer's microphone input. The result is that loud sounds will be much louder than they should be and soft sounds will be much softer than they should be. The end listener has no control over this problem in cases where the podcast is downloaded unedited. If an edit is made during post-production then the recorded audio levels can be fixed before distribution of the final product.

Conclusion

Although audio podcasting does not require much in the way of specialized equipment or technology, in practice it is more difficult for a new user to achieve a production-quality podcast than it is for audio professionals. The popularity of webcasting has led to the development of RSS readers and dedicated applications such as Podcast Aggregator and Google Currents, which are intended to be used as an easy way to enable podcasters to upload their shows online, store them online and manage their subscriptions while on the go. However, these services are mostly geared toward professional broadcasters rather than hobbyists. Many users who wish to get started without having to invest in high-end audio equipment will find that more basic hardware such as USB microphones can be used.