PoducateMe: Practical Solutions for Podcasting in Education
123
Printable copies of the guide are available for purchase and immediate download at
readjust their volume slightly, but these manipulations are pretty minor and should take
but a few minutes to perform.
Whatnot
Sometimes, podcasters will incorporate into their episodes audio files sent in by listeners.
These files may be the listener recording himself asking a question and emailing the file
to the podcaster directly or via a Web voice mailing service such as K7.net or
GotVoice.com. Either way, educators can easily solicit questions and comments from
students and import the files into Audacity for inclusion in the podcast. It takes a little
more production work to add this content, but it does serve well to involve students in the
project and promote a sense of mutual ownership.
If you do decide to incorporate material from other sources into your podcast, do your
best to keep the volume of this foreign content consistent with that of the rest of your
show. As demonstrated earlier, you can use Audacity’s Envelope Tool to accomplish this
task.
Exporting an Audio File From Audacity
We’re now ready to export our podcast episode from Audacity so that we can prepare it
to post on the Internet. This step is pretty easy. First, make sure that all tracks are
deselected (you can deselect tracks by clicking in the gray area below all the tracks).
Next, select File > Export As AIFF from Audacity’s menu bar.
You’ll receive a warning message that all tracks will be combined and exported into a
single mono file. Click OK and save the file in an appropriate directory on your computer.
See, I told you this step way easy!
File Compression
File compression is not the same as dynamic range compression. While dynamic range
compression is used to tighten up your waveform, file compression is performed to
reduce the file size of your recording. As discussed earlier, there are a number of audio
file compression schemes available, and each has its advocates and detractors. For
podcasters, MP3 has emerged as the standard compression format. However, as noted
earlier, the AAC format is used to create enhanced podcasts.
If we look at the size of an example AIFF file, the 15 minute, twenty-four second
recording weighs in at 116.7 MB—much too large for our purposes. So, we’ll decrease
the file size by converting it to MP3 and, in the process, toss out some of the less critical
information in the recording. Sound quality is always somewhat degraded during file
compression, but we try to minimize the impact by defining the information to be deleted.
After we compress our file, it will weigh in at a more Web-friendly 12.4 MB.
