How to Listen to More Podcasts in Less Time

Note: This is the first post of a two-part series.  Part two will provide specific instructions on how to use Audacity to listen to more podcasts in less time and will be available on Monday, November 24th.

If you're listening to a lot of audiobooks or spoken-word podcasts, here's an easy way to get through more audio in less time: speed up the tempo* of your files (AKA time-compression).  For example, using time-compression, I can listen to audio in about 3/4 of the time it would normally take.  This means I save 6 hours of listening time for every 24 hours of audiobooks or podcasts that I listen to!

*It's important to note here that I'm talking about changing tempo, but not changing pitch.  If you just indiscriminately speed up your audio, you'll get something that sounds like Alvin and the Chipmunks are narrating your piece.  If you just speed up the tempo, you'll get something that sounds like the lawyer-talk fine-print at the end of radio advertisements (although you don't have to speed it up to the point of incomprehensibility, as they do).  It's also important to note that this won't really do justice to music, so you probably do not want to apply any of the following tips to any music podcasts you have.

Why speed up your audio? 

Besides the obvious point that you can listen to more audio in the same listening period, some studies [link to MS Word document] show that time-compression can even improve comprehension for listeners, who find that they are less distracted when the audio is faster-paced (giving their minds less time to wander between important points in the audio).  Of course, some subjects find their comprehension suffers when listening to time-compressed audio, so your mileage may vary.

How to do time-compression:

You can either do time-compression on the fly (in your music player), or speed up your audio before you listen to it.  The option you choose is dependent on what hardware you have and how much you want your audio compressed.

1. On-the-fly compression:

Some hardware music players like the iPod have the ability to speed up the tempo of audio on-the-fly.  The iPod specifically can increase the tempo up to 120% of the normal speed, which would cut 10 minutes off of every hour of listening you do.  As a benefit, on-the-fly compression means you can toggle it on/off at will, so you can revert back to normal speed if things get moving too fast, and speed things up again when you're ready.  Some other hardware players also have this feature built in - check your user's manual to see if your player can speed up your audio.

Some software music players also can do on-the-fly compression.  Quicktime (even the free version) is an example that allows you to do realtime compression, anywhere from 0.5 x normal speed to 3 x normal speed (spoken audio is probably intelligible up to about 1.5 x normal speed).  As an added benefit, this technique should work for both audio and video on Quicktime.

As the name implies, by doing your time-compression in pre-processing, you're creating a new audio file to listen to at some later point in time.  The benefit to this method is you can create an audio file that is at the custom speed you want to listen to, and then play it anywhere.  However, because you will have created a new file, you won't be able to speed up or slow down the file once it is created (unless you combine this with an on-the-fly method listed above).

There are a number of programs available to time-compress audio files.  My favorite among these is Audacity, the open-source audio editor program. Please go here for step-by-step instructions on how to use Audacity to time-compress your audio files.  Other programs I have heard of and/or tried include Amazing Slow Downer and AV MP3 player morpher - both of these do the trick, but are not my tool of choice.

1. It's a good idea to always preview your file before you compress it.  That way you can fine tune how much you will compress the audio to ensure you're not going to speed up the audio past the point where you can understand it.
2. Start with a minimal time-compression and work your way up to a faster speed.  You'll soon find a speed you're comfortable with, and you'll start to hate listening to regular-speed audio because it seems to drag!
3. If you're looking to change a lot of different audio files, look for a method that allows for batch operations, so you can transform multiple files without having to manually change each one.  AV MP3 player morpher has this ability by default, but I prefer the beta version of Audacity, which also lets you do a batch conversion very easily.  I'll have a whole post on how to do this in Audacity next week, in part two of this post.
4. If you're really handy around a computer, you can always join multiple files together into one big .mp3 file, prior to time-compression.  This would be handy, for example, with audiobooks or serialized podcasts that have chapters.  Again, you can use Audacity to join files, or a program intended for this kind of activity, like MP3 Splitter & Joiner.

NaBloPoMo 2008!