Imagine if your favourite radio programme were broadcast only when you were unable to listen but, fortunately, was made available as a podcast or mp3 download. You begin to download, building up an increasing collection but seem seem unable to make the time to enjoy them. You consider putting them onto CD to listen to in the car. A blank CD holds 80 minutes of audio. However, the programme lasts 45 minutes and putting one episode on a CD, leaving 35 minutes worth blank, doesn’t fit in with your generally planet-saving outlook (let’s worry about the car thing another day).

Never fear – Audacity is here – and free. As a precursor to shortening the file to just under 40 minutes – we will also amplify it to avoid having to turn up the volume of the in-car entertainment system, which might invite hiss into an otherwise perfect world – in addition to taxing your car battery a little more. Who needs that in this approaching winter of discontent?

• Open the folder where the multitudinous files are hoarded

• Choose one and Right-click the name of the mp3 file

• Left-click Open With

• Left-click Audacity

• From the Edit menu choose Select all (keyboard shortcut Ctrl+A)

• Go to Effects menu and choose Amplify (Alt+C then A)

• The optimum amount will be offered, so simply click OK (or press Enter)

• Ensuring that the Select All situation is still in place (the continued darkening of the image of the sound wave should confirm this) – return to the Effects menu and choose Change Tempo (Alt+C then C,C,C). The word tempo is essential because, should you choose, Change Speed, the pitch of the voices (or notes) will rise – this adds little to a serious documentary – unless its a biography of the element Helium.

• Drag the slider to the right until percentage increase is 6% – to some this moment seems counter-intuitive because we hope to shorten the file but we appear to be adding 6% to the original. Remember we are increasing the tempo – not the length

• Go the File menu and Export the file as an mp3. Audacity saves in its own file format (ogg) so be sure to Export as opposed to saving – otherwise you will be unable to open the file in another program. The very first time you Export as an mp3 in Audacity, a message will appear explaining that you need to hunt down a supplementary application entitled Lame from the Internet. This is quite straightforward, and has to be done only once. If you feel in any way uneasy about this, the alternative is to Export as a wav. This, at first seems an unnecessary waste of your hard drive (an mp3 is 1/10^th the size of its wav version). Remember that as you intend to create CDs you needn’t keep the files on your computer.

• The exporting process should aim your file at the folder from which it was taken – and its original name will be offered. Rather than dreaming up a new one, creating an expanding universe of confusion, I tend to use that name, adding the suffix dim (for diminished). That way both files will appear together in the folder. You might choose to delete both which is easier when they are neighbours.

• When your have diminished two programmes, it’s time to open them in iTunes (other Media Players are available)

• Create a New Playlist (Ctrl+N) and give it a name which combines both programmes. Drag both files into the folder. This new folder/playlist can also be deleted once the CD has successfully been burned.

• With this new playlist selected (you’ll know this has successfully happened because only the two chosen programmes will appear in the right pane. Insert a blank CD into the drive and choose Burn Disc – depending on which version of iTunes you have, the location of this command varies

• You now have just under 80 minutes of mind-improving audio material to brighten up the most routine journey. There’s no better condition in which to arrive at your work than fascination.

• If you are truly in planet saving mode then pass the CDs onto your friends or form a group of like friends to share the conversion.