A track is like one instrument in your symphony, or one voice in your podcast. You can add more tracks, and all of them will be mixed together to create your final output, but during editing you can manipulate each track independently. If you have an interview recorded with two microphones, each one can go in a separate track. If you have background music, that could go in a third track. You can move the whole track along the Timeline so that it plays at a different point in time in the mix, but until it is split into clips you cannot move individual parts of it around.
Each audio track containing digital audio presents from left to right:
- a Track Control Panel
- a vertical scale with units (except in the Pitch view)
- a visual representation of the audio (by default this is the Waveform view as in the images below).
New tracks are created whenever you import an audio file, record (except for Append Record) or generate audio when there is no selection.
Tracks > Add New lets you explicitly add a new, empty mono or stereo audio track.
Stereo Audio Track
This image shows the separate components of an Audacity stereo track: the Track Control Panel, the Vertical Scale and the Waveform Display itself, typical of a finally edited recording. As per convention, the upper waveform and vertical scale represent the left channel and the lower waveform and vertical scale represent the right channel.
In a stereo track, all editing actions on the track are applied identically to both tracks.
Single Audio Track (mono, left or right)
A single audio track has the same components as a stereo track with a single waveform and vertical scale rather than two. This can be easily seen if using "Split Stereo Track" in the Track Drop-Down Menu to split the stereo track into two single tracks. The same menu can make single tracks mono, left or right. Each single track can be separately selected and thus edited independently from other tracks.
The vertical scale displays amplitude when showing the waveform, frequency when showing the spectrum or is empty when displaying pitch. The amplitude scale shown is the default linear scale, with 1.0 being the maximum value of positive signals and -1.0 the maximum of negative signals. If the display is changed to Waveform dB in the Track Drop-Down Menu, the scale shows dB values for positive signals only, ranging from maximum 0 dB to the minimum dB level set in Interface Preferences. When the mouse pointer is over the scale it changes to a magnify icon.
- Left-click in the Vertical Scale for any Waveform or Spectrogram view to zoom in. The range displayed on the scale will be centered at the value you clicked at. Left-click and drag a region up or down then release to zoom into that region.
- SHIFT-click (or right-click) to zoom out. This is a zoom in the vertical direction, as opposed to a horizontal zoom on the Timeline. See Zooming for more details of vertical and horizontal zooming.
Splitting and Joining Tracks
Using the Track Drop-Down Menu you can:
- split a stereo track into separate tracks for left and right channels
- split a stereo track into two separate mono tracks
- join two mono, left or right tracks into one stereo track.
For example, here is a project with two mono tracks:
After selecting Make Stereo Track from the Track Drop-Down Menu on the upper track we get one stereo track:
Click and drag between the two waveforms to change their relative height.
Changing the height of the channels in a stereo track: Click and drag between the channels.
Changing the height of a track: Click and drag between the tracks.
The Track Control Panel
The Track Control Panel at the left of the audio track has controls and status indicators for this track.
Clicking and dragging other than on a control moves the track up or down in a project containing multiple tracks (to do this with the keyboard, use one of the "Move Track" commands in Track Drop-Down Menu).
Clicking this button will close the track, removing it from the project.
Track Drop-Down Menu
Clicking on the track name shows the Track Drop-Down Menu giving various options that affect this track only. Newly created tracks are named "Audio Track". Options in the drop-down menu include changing the name or sample rate, how the track is displayed and splitting a stereo track to single left, right or mono tracks.
Click to silence this track when playing. Click again to unsilence. Muted tracks are not exported.
Click to play just this track. Click again to cancel. Solo takes precedence over mute - the mute buttons usually have no effect whilst any solo button is down. There are three options for exactly how the solo button operates, described in Tracks Preferences. One of the options is not having the solo button at all.
Set the gain for this track. Hold down the shift key while dragging to adjust the slider in finer increments. Double-click the slider to bring up a window where you can make precise adjustments or enter a gain value
To make signal stronger on left or right earphone. Hold down the shift key while dragging to adjust the slider in finer increments. Double-click the slider to bring up a window where you can make precise adjustments or enter a pan value.
Track Collapse Button
Click on this to make the track 'fold up' into a smaller size. Click again, or drag the lower edge of the track to restore the size.
Track Info Area
Gives in order, Stereo or Mono, the sampling rate in Hz and the manner in which samples are represented.
When present, indicates that this track is part of a Sync-Locked group.