Click the red recording button to create an empty stereo track and start the recording. To change the standard parameters, make the desired settings under ‘File’+‘Preferences’. ‘Audio I/O’ and ‘Quality’ are important for the recording. Even if tracks already exist, pressing the recording button creates new tracks. Initially, this may be confusing, because these tracks cannot be seen in the standard-size program window.

To import audio files, select ‘Project’+‘Import Audio’. The program supports the WAV format and the compressed Ogg Vorbis format. See Section 13.3.3, “Compressing Audio Data” for more information about this format.

Open the ‘AudioTrack’ menu to the left of the track. This menu offers various options for different views and basic editing operations. To rename the track, select ‘Name’ and enter a new name. The different view modes offered by Audacity include ‘Waveform’, ‘Waveform (dB)’, ‘Spectrum’, and ‘Pitch’. Choose the one suiting your needs. If you want to edit each channel of a stereo track separately, select ‘Split Track’. Each channel can then be treated as a separate track. Set ‘Sample Format’ (in bit) and ‘Sample Rate’ (in Hz) for each track.

Before you can use most of the tools offered in the ‘Edit’ menu, first select the channel and the segment of the track to edit. After making your selection, you can apply all kinds of modifications and effects to it.

Depending on the chosen file type, various view formats for segment selections are offered under ‘View’+‘Set Selection Format’. With ‘Set Snap-To Mode’, the segment boundaries can automatically be adapted to the selected view format. For example, if you select ‘PAL frames’ as the view format and activate ‘Snap-To’, the segment boundaries are always selected in multiples of frames.

All editing tools come with tool tips, so should be easy to use. The ‘Undo History’ function, accessed with ‘View’+‘History’, is a useful feature for viewing recent editing steps and undoing them by clicking in the list. Use ‘Discard’ with caution, because it deletes editing steps from the list. Once discarded, these steps can no longer be undone.

Figure 13.11. The Spectrum

The built-in spectrum analyzer assists in quickly tracking down any noises. View the spectrum of the selected segment with ‘View’+‘Plot Spectrum’. Select a logarithmic frequency scale in octaves with ‘Log frequency’. If you move the mouse pointer within the spectrum, the frequencies of the peaks are automatically displayed together with the respective notes.

Remove unwanted frequencies with ‘Effect’+‘FFT Filter’. In connection with the filtering process, it may be necessary to readjust the signal amplitude with ‘Amplify’. Additionally, use ‘Amplify’ to check the amplitude. By default, the ‘New Peak Amplitude’ is set to 0.0 dB. This value represents the highest possible amplitude in the selected audio format. ‘Amplification’ shows the value needed to amplify the selected segment to this peak amplitude. A negative value indicates overamplification.

To save the entire project, select ‘File’+‘Save Project’ or ‘Save Project As’. This generates an XML file with the extension .aup, which describes the project. The actual audio data is saved in a directory named after the project with _data appended.

The entire project or the currently selected segment can also be exported as a stereo WAV file. To export the project in Ogg Vorbis format, refer to the information in Section 13.3.3, “Compressing Audio Data”.