Podcasting

What is podcasting?

  • Technically speaking podcasting is making files (usually audio, but not exclusively) available online with RSS feeds. RSS feeds allow a “subscriber” to get an automatic update at regular intervals when new content is available, instead of having to return to a web-site on a regular basis to download new content.
  • Commonly speaking, although it’s not correct, podcasting has come mean any audio files that can be downloaded or streamed from the internet and played (either on a computer or mp3 player).
  • If media other than audio is involved in the podcast it usually takes on a different name. VODcast is used for video podcast, and a podcast with images and links is referred to as an enhanced podcast.
  • Podcasts are typically updated/read/received with an RSS aggregator - for the purposes of podcasting this tool can also be called a “podcatcher.” This is an application like iTunes, or Juice (formerly iPodder), and many others.
  • So, the bottom line is that a Podcast is just a media file (usually audio) and an RSS feed. You make it come to you, by subscribing with a Podcatcher, so you can listen or view it when you want to - this is often referred to as “time-shifting.”


Who can podcast?

  • Anyone with a computer that can (at least) record audio, and is connected to the internet.


Who can listen to podcasts?

  • Anyone with a computer that can play audio and an internet connection.
  • You do *NOT* need an iPod or even a Macintosh
  • You do *NOT* need an mp3 player in many cases (because you can listen to podcasts on your computer).


What sort of material is available?

  • Audio: Essentially any audio that can be recorded can be turned into a podcast. Lectures, speeches, readings, conversations, shows, guided tours.
  • Images: if you’re viewing a podcast on a computer (via iTunes for example), or on an iPod that can display pictures, you can see images that are included in an enhanced podcast.
  • Video: if you’re viewing a podcast on a computer (via iTunes for example), or on an iPod that can display video, you can see videos that are delivered as a VODcast, or video-podcast.


What podcasts are out there already?

  • Thousands already exist; typical places to find them include:
    • Apple’s ITMS
    • iPodder.org
    • PodcastAlley
    • Podcasting News
    • syndic8 (mostly rss feeds but podcasts as well)
    • Daypop (mostly rss feeds but podcasts as well))
    • Often you can find links on homepages to subscribe to rss feeds as well.


What can be done with a podcast?

  • Essentially anything with a primary audio component including:
  • On-demand shows (audio and video)
  • Blogs with audio or video content
  • Audio books
  • Audio tours with additional image (or even video) content
  • Educational content
  • course lectures, course discussions, language labs, study support tools, music courses, interviews, speeches, other university-related events.

  • Storytelling
  • Speeches


What else can be done?

  • Distribute audio along with other text based products.
  • Political podcasts
  • Commentary podcasts (similar to turning on the directors comments on a DVD)
  • Conference Announcements/Alerts
  • Medical care (updates and summaries of important articles)


What are the pros of using a podcast?

  • Time-shifting: you can listen/view the material when you want, instead of at a particular time when it might be aired.
  • Students can re-visit past lectures as a study aid or listen to classes, or parts or classes, they missed (example: those late-comers!)
  • Access to course materials is more flexible - reduced dependence on locations such as a lab or library - students can revisit these lectures, or use the study aids while at the gym, or commuting to and from class.
  • Relatively easy to use, and effective, for multiple recording purposes (interviews, field notes, etc.)
  • Greater student interest and engagement.
  • Greater support for individual learning needs.


What are the cons of using a podcast?

  • Issues around where it will be stored, access and copyright.
  • A decent connection is needed to download the files in a timely manner.
  • Primarily audio files, so limited usefulness for those with hearing impairments.
  • Not designed for two-way communication.
  • Quality can very greatly since anyone can make and publish a podcast.

Pod Casting - Recording & Saving Audio


Recording Audio

 

Getting Audio “in” to the computer

There are a number of ways you can get audio onto, or into, a computer. Two of the most common would be recording audio directly into your computer, or using a digital audio recorder and then transferring the files to the computer after they’re recorded.

To record audio directly to your computer you need to see if you have an “audio-in” port or jack. Look on the front and back of your computer, it might be designated by the word “mic” or with an icon of a microphone, and typically is a mini-jack (like what you’d expect to plug headphones into). If you have one then you can plug a microphone into it - which you can purchase at most computer or electronics stores, and record your audio.

If you don’t have an “audio-in” option on your computer, or you simply prefer not to record it there, you could also record your audio into an digital recorder and then transfer it to the computer (usually with a usb cable). There are many models of recorder, be sure to get one that record decent quality audio, even if the file type isn’t exactly what you’ll want in the end. Because it’s entirely possible to convert a file from one format to another, but it’s not really possible to enhance the quality all that much after it’s recorded!


Applications:

There are a number of applications that will allow you to record audio directly into your computer, as well as convert audio you’ve transferred to the computer from another device.

If you do not have a program that will save/export audio files as mp3s we recommend Audacity. It’s a free, cross-platform, and a wonderfully easy to use application. It will let you record, edit and save your audio as an mp3.

The ultimate constraint, with regard to podcasting, is that you need to be able to export the audio into a format that will be useable by your intended audience… the best bet, therefore, is an mp3. This is because iPods, mp3 players, and computer all will play a standard MP3 with little to no additional software needed.


Environment:

Where you record your audio is just as important as the content itself. Some situations can’t be helped, but if at all possible you should be sure you’re in a quite room with a decent quality microphone attached to your computer (or audio recorder). If you’re in a noisy place you might consider using a lavaliere mic, or some other means of focusing on your voice and not the other noises that might be going on around you.


Quality:

There are quality settings to audio recordings, just like the resolution of an image. And just like an image, there are different kinds of settings… they include the following:


Sample Rate

Generally speaking this is the number of units the recording is broken into. To liken it to images again, it’s like setting the number of pixels in an image. You set the number of samples (of the music) that are recorded each second. This, in turn, allows for a certain number of frequencies to be reproduced by the digital sound. The more samples you have, the higher the frequency you can produce. Commonly used rates are:

Sample Rate

Description

44.1 kHz

CD Quality - able to produce frequencies that span full range of human hearing.

22.050 kHz

1/2 CD Quality - great for speeches and some music, or a mix of the two (not fully quality but perfectly adequate for many purposes).

11.025 kHz

OK for voice, some noticeable “digital” sounding effects.

8 kHz

“telephone quality” - again, OK for voice, but sound may be somewhat muffled.

 

Sample Format (16 or 32 bit in Audacity)

It’s a setting the dictates how the samples get written as a file. 16 bit is CD quality, but 32 bit is more flexible. The recommendation is to record at 32 bit (as long as you have the space on your computer) and then save version out at the lower quality.


Stereo vs. Mono

Stereo and mono are options you may have when you record audio. The inclination would be to choose stereo, since we all think that sounds better. But mono will still play through both speakers, it’ll just be the exact same sound. In truth mono might sound a slightly muffled, but it’s hard to notice unless it’s pointed out, or you’re an audio engineer (grin).

Anything that is CD quality or higher will more than likely be adding nothing more than file size to your podcast. CD quality audio is 44kHz, 16bit, stereo sound (in some applications all your given is a bit rate, 192kbps would be about CD quality audio). In most cases you can get away with sound that’s about half that quality and still hear little to no difference. The best rule of thumb is to test a few quality settings but exporting them and listening to your audio… shoot for the lowest file size you can get without sacrificing more quality than you, and your audience, can live without.

 


Saving Audio

 

Exporting (or Saving) your Audio Files (generally as an MP3)

When exporting an MP3 it pretty much all comes down to the bit rate. The bit rate controls how much data (per second) is in the file and therefore get’s played. This, therefore, translates into how many samples are in the file, which translates to file size and sound quality.

Bit rate

Quality

Average Size
(per minute)

Example’s
File Size

192

Almost CD quality

~1.5MB

176K

128

typical for many mp3s (near CD quality)

~1MB

120K

112

typical for digital radio

< 1MB

104K

64

FM radio quality

~ 500KB

60K

32

AM radio quality

~ 250KB

32K

16

Short-wave radio

~ 100KB

16K

Add Your Meta-Data:

It’s a word that many people are familiar with these days, and to some people being told to add it is almost like hearing your Mom say “east your vegetables!” But, if you don’t already know, it’s data about the data (or file), and, just like vegetables, it’s really important. With audio files, like mp3s, you can encode ID3 tags to help an application that plays audio understand your file better. It also will provide the user with pertinent information - such as the title of the file while it’s playing on their mp3 player or in there player on the computer. There are many tags, but a good set to use are these:

  • Song Title: set to your podcasts episode title
  • Artist: set to your name, the author of the podcast, or the copyright holder.
  • Year: the year you created this podcast episode
  • Track number: the episode number (first, second, third…)
  • Album: Title of your podcast
  • Comments: Anything you’d like, but a link to your podcast’s web site would be a great idea! Remember whatever you do add will add size to your file
  • Genre: Podcast

Pod Casting - Publishing Pod Casts & RSS Feeds


Publish It

 

This is the easy part!

Once you’ve build your RSS feed and prepared your audio files, all you have to do is move them to your web site. Poof! You’re done. Send the URL to all your friends and family, and tell them you’re syndicated… OK perhaps you’ll just be posting the link in Blackboard for your students to access the Podcast, but you get the idea!

Once the files are on your server you can also list your podcast in the directories we talked about back in the overview section… they each have different processes for adding your podcast to their directories so please refer to each site for specifics. Some might ask for you to make a slightly different RSS feed file (like iTunes, because it has some additional special tags) - but generally speaking, you’re done!

 


RSS Feeds

 

What are they?

RSS actually can stand for a few different things, but in this context “Real Simple Syndication” makes the most sense, and is the easiest to remember. It means that you’re making a file/site that others can subscribe to and subsequently be notified of any additional materials you add to the file/site.

The actual ‘file’ is an XML file. If that scares you, it really shouldn’t… it’s a super-tame XML file. If you’ve ever made a basic HTML page by hand, or even just understand the basics of HTML, you’re all set. If you don’t fall into the aforementioned category… still no worries, I promise you’ll pick it up in no time!

The RSS feed/XML file is just a series of “container” tags. They look like this where the word, in this case “tag” is a “base” for each. The first tag (without the /) says “open” or “start” this tag. The second tag (with the /) says “close” or “stop” this container. Got it? Well then, that wasn’t so hard was it?

Now all you need to know is that there are a few specific container to use, and you’ll be all set. It’s more or less like picking the right size tupperware bowl for the left over spaghetti. Because with podcasts you need to use to specific containers to hold specific types of content. Some also have “sub-containers” in them. Think of it like Tupperware with divisions. It’s all in the big plastic container, but each things has it’s own little sub-section… so each thing needs it’s on container tag. So what are the tags? Here’s a list, as they should appear in your RSS feed/XML file.

  • <?xml version=“1.0” encoding=“UTF-8”?> - this lets the browser (or rss aggregator) know that the file is xml and uses utf-8 which is a standard to help make the bits and bytes that make up the characters (abc… etc) standard.
  • <rss></rss> - this goes around the entire document (except for the xml tag above) to say the contents are all RSS feed materials.
    • <channel></channel> - this goes inside the RSS tag, around everything as well, to say all the contents are part of this channel, who’s properties will be defined by the next few tags
      • <ttl></ttl> - (only inside channel tag) stands for time to live, and sets up a refresh rate for your subscribers to be notified of modifications to your RSS feed.
      • <title></title> - (in both the channel and item tag) when it’s inside the channel tag, it defines the title of the entire podcast
      • <link></link> - (only inside channel tag) is a link to your web site, if you have one, or general information about the podcast - it has to be on a webserver, so you’ll have a link!
      • <language></language> - (only inside channel tag) declares the language you’re using (english, french, spanish…)
      • <copyright></copyright> - (only inside channel tag) allows you to add in copyright information.
      • <managingEditor></managingEditor> - (only inside channel tag) allows you to add in an email address for audience members to contact you if need be.
      • <description></description> - when it’s inside the channel tag it defines the description for the entire podcast; when it’s in the item tag, it defines the description for an episode.
    • <item></item> - allows you to define a subset of tags to describe a particular episode of your podcast

      • <author></author> - (only inside item tag) allows you to add in an email address of the author of the podcast (can include name in parenthesis).
      • <title></title> - (in both the channel and item tag) when it’s in the item tag, it defines the title for an episode.
      • <enclosure></enclosure> - (only in the item tag) allows you to associate a media file with the item tag/episode of your podcast.
      • <guid></guid> - (only in the item tag) allows you to associate a link with the item tag (I usually make it the same as the link inside the enclosure tag)
      • <pubDate></pubDate> - (only in the item tag) allows you to associate a date with the particular podcast episode. Must follow the “RFC 822” specifications… which means it must look like this: Mon, 14 Nov 2004 13:09:34 EST - otherwise is can cause errors.

You can see an example of all this code put together (as a graphic) here: RSS code example

There are also a number of other options. Some are free others are not. A few are listed below:

Pod Casting - Glossary

  • Enhanced Podcast - a audio podcast that also contains images or web links.
  • iPod - An Apple product. It started out as an mp3 player, now it will also play video. It’s where the pod in podcast comes from.
  • Media File - in this context an audio or video file. Popular formats include:
    • MP3 - audio
    • M4A or M4B - enhanced audio (can contain images and web links)
    • MV4 - video files
  • MP3 - a type of compression applied to audio files. It makes them very small, but still allows for good sound quality.
  • Podcasting - using an RSS feed to allow users to subscribe to a list of your media files.
  • Podcatching - a term used to describe the process of receiving media files from a particular podcast.
  • RSS aggregator - an application that will “watch” a subscription list that is created by a user. The user can specify whether they simply want to be notified of new additions to a particular RSS feed or, instead, that they would like the aggregator to download the new content.
  • RSS/ RSS feed - stands for Real Simple Syndication (although there are some people who would argue that point). Essentially it’s an XML file that lists different “articles” or “items.” These “feeds” can be subscribed to (with an RSS aggregator) and then the subscriber will be notified when additions are made to the XML file. RSS feeds are used for News (text and images) as well as podcasts.
  • XML- stands for eXtensible Markup Language. It looks a lot like HTML but it very powerful because you can, essentially, encode your data to specify different parts or subsections.
  • VodCast - another name for a video based podcast