Audio Tracks

Bill 26Nov11: settle on the image of a stereo track with annotations.

• Peter 27Nov11: not so sure about using an image of a very saturated waveform (it nearly touches the 1.0 at some point). This is also true of the other images on this page.
  • Gale 28Nov11: Bill says it's typical of an imported (finished) file and I agree.
• Peter 27Nov11: On a point of detail I note that your track is named "Stereo Trac" - is that the default on Mac? On Windows my default stereo (and mono) track name is "Audio Track". I thought that policy was to use default settings and displays for images in the manual as far as possible? The other images on this page use the "Audio Track" nomenclature.
  • Gale 28Nov11: Definitely we want defaults for Preferences. Track names can be called anything. I'd be about +0.2 on changing it to "Audio Trac" (as it will appear). If Bill prefers to leave the image as it is and close this ToDo-2, that's fine also with me.

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

ToDo-2

• Gale 28Nov11:

  Thanks all for the work on the image. Looks good. See the editornote at the top with its own "todo".

  Looking at the question of a mono track image, I do have some sympathy with Ed's point of view. There is little here to suggest mono (meaning "single") tracks are even supported until carefully read through, and nothing on left and right. I've also come to the conclusion that splitting stereo tracks is a) probably addressed too late on this page b) probably isn't documented well enough without at least one image somewhere of the process - there is none on Track Drop-Down Menu. Also there is an overlap here with "Stereo Tracks" in Audacity Tracks and Clips - should that have our new annotated image? Do we need the bit on "can't edit channels of a stereo pair separately" here as well? For now I added that, tweaked the short description of Track Drop-Down Menu further down the page and put a short (no image yet) section for "Single Audio Track (Mono, Left or Right)" in an editornote, Would an image of left above right help that section?

The image below 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.

See Audacity Waveform for further details of the waveform display.

In a stereo track, all editing actions on the track are applied identically to both channels.

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 be separately selected and thus edited independently from other tracks.

Bill 28Nov11: So do we want to demonstrate splitting and joining tracks here?

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).

Controls

• Close Button:
  

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.

• Mute Button:
  

Click to silence this track when playing. Click again to unsilence. Muted tracks are not exported.

• Solo Button:
  

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.

• Gain Slider:
  

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.

• Pan Slider:
  

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.

Status Indicators

• Track Information Area:
  

Gives in order, Stereo or Mono, the sampling rate in Hz and the manner in which samples are represented.

• Sync-Lock Indicator:
  

When present, indicates that this track is part of a Sync-Locked group.

Vertical Scale

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.

Display

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.

See Audacity Tracks and Clips for more details on using the waveform display.