Contributed by: Florian Henning (UNU-MERIT / MGSoG / FHS)
Audacity is an open source tool for recording and editing audio. It is a really useful tool for dealing with any kind of audio data, and freely available on the sourceforge website.
I use audacity quite a lot for my own research interviews. In order to have an accurate account of the interview, I record my interviews, and afterwards transcribe them, i.e. type out the audio recording as text. Audacity is a useful tool for several steps in this process.
First of all, audacity lends itself as a tool for the actual recording of your interview, only using your laptop and the built-in microphone. Personally, I prefer to use a small hand-held recorder because I find it much less intrusive, but audacity provides a really well-functioning solution if you don’t have a recorder available. Before starting, you should make sure that you have sufficient space available on your harddrive (audacity uses about 50MB for 1h of interview time). The next step is to check that the right audio input is selected in audacity’s preferences (typically your laptop’s built-in microphone, see Fig.1). To record, simply hit the big red record button in audacity’s main window, and you’re “on air”. In case you need to pause the recording, I’d recommend using the pause button instead of the stop button. Once your interview is over, press stop. You can then save your recording by selecting File>Export as WAV (or MP3).
Fig.1: Selecting the correct audio input in audacity
Audacity also features some powerful effects that you can apply to the recording to (sometimes drastically) enhance the quality and make it easier to understand for transcription purposes. To apply any effect you first have to select the entire recording (click into wave graph and press Ctrl+A). Then select the desired effect from the menu bar and tweak its settings until you’re satisfied with the result:
First, when you have an audio recording where the dynamic range is too wide (e.g. one speaker speaking with a very low voice, the other one talking very loudly, a common situation I experienced with recordings of phone interviews), you can apply Audacity’s Leveler Effect (try moderate to heavy leveling, and a high threshold for noise, say 60-80 dB).
Second, the Noise Removal is also a very useful effect, especially with phone recordings. (Note that it only works with “constant” noise such as white noise, not with “punctual” noise such as a car driving by etc.). For this, simply follow the instructions in the effect window and leave it with the default settings.
Third, audacity allows you to slow down the tape by going to Effect>Change Tempo, and set the slider to a setting you like (try -35%). You will find that you can now almost type along, without having to rewind! If you do need to rewind or pause, try these shortcuts for quicker handling:
, or . rewind/fast forward 1 sec
SHIFT + , or SHIFT + . rewind/fast forward 10 seconds
P pauses the tape
ALT + TAB (Mac: CMD + TAB) switch between windows (e.g. audacity and word editor
In short, audacity is a great tool when you have to deal with audio data in your research, and it’s free! There are many more functions to explore than I explained here, so if you know of additional tricks or tips, please SHARE-IT with us by using the comment box below!
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