User:Billw58/Audio Tracks

Each audio track containing digital audio presents from left to right: 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.
 * 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).

About Tracks
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.

Stereo Audio Track
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.
 * Stereo Track annotated L&R.PNG

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 separately selected and thus edited independently from other tracks.
 * [[Image:Track_example_mono.png|Mono Track image]]

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.

See User:Billw58/Splitting and Joining Tracks for more information.

Track Control Panel



 * -valign="top"
 * [[image:TrackPanelNew.png|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).
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Controls

 * Close Button:
 * [[image:TrackClose.png|Track Close Button]] Clicking this button will close the track, removing it from the project.


 * Track Drop-Down Menu:
 * [[image:TrackDropDown.png|Track Name]] 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:
 * [[image:TrackMute.png|Track Mute Button]] Click to silence this track when playing. Click again to unsilence. Muted tracks are not exported.


 * Solo Button:
 * [[image:TrackSolo.png|Track 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:
 * [[image:TrackGain.png|Track 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:
 * [[image:TrackPan.png|Track 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:
 * [[image:TrackCollapse.png|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:
 * [[image:TrackInfo.png|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:
 * [[image:TrackSync.png|Track Sync-Lock Indicator]] When present, indicates that this track is part of a Sync-Locked group.

Vertical Scale



 * valign=top|[[image:TrackVertRuler.png|Vertical Scale]]
 * valign=top style="padding-left:10px"|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.
 * valign=top style="padding-left:10px"|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.
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The Waveform Display
The waveform display uses two shades of blue, one darker and one lighter.


 * The dark blue part of the waveform displays the tallest peak in the area that pixel represents. At default  zoom level Audacity will display many samples using only one pixel width, so this pixel represents the value of the loudest sample in the group.
 * The light blue part of the waveform displays the average RMS (Root Mean Square) value for the same group of samples. This is a rough guide to how loud this area might sound, but there is no way to extract or use this RMS part of the waveform separately.


 * [[Image:WaveAnnotated.png|image of waveform with peak and RMS regions indicated]]

If you zoom in far enough the light blue display will disappear, because there are not enough samples to provide a meaningful average in the region being displayed. The line you see now represents the peak level of the samples, that is the top of the darker part that you saw when you were zoomed out.

Below is an example of a dark blue only waveform, obtained by zooming in about 12 times. The waveform can now be clearly seen as joining together many individual sample points (the dots).
 * [[Image:TrackZoomedToSamples.png|image of track zoomed in to see the individual samples]]

Waveform (dB) view
The waveform display can be switched to a dB logarithmic  view by clicking on the track name (or the black triangle) in the  Track Control Panel.

The default linear Waveform display is very convenient for editing since the majority of audible work is on the screen. When zoomed in edit points are easy to find. However, the linear waveform doesn't correspond to the way your ears work--they sense quiet sounds more effectively. Halving the volume on the linear scale (for example, deamplifying a sound with a peak of +/- 1.0 by -6 dB to bring it to +/- 0.5 on that scale) doesn't sound all that much quieter. Human hearing would need a reduction of -18 dB to make audio "appear to sound" half as loud.

The following example is exactly the same recording as that above displayed in Waveform (dB) view.
 * [[Image:TrackExampleDB.png|image of track in Waveform (dB) view]]

A waveform with clipping
Below is an example of an oversaturated recording where clipping has occurred, that is, the signal has exceeded the maximum allowed level. The vertical red lines show where clipping has happened; these clipping indicators can be turned on and off (Audacity default setting is "off") by selecting View > Show Clipping.


 * [[Image:TrackExampleClipping.png|image of stereo track showing red clip indicator lines]]

Resizing Tracks
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.
 * [[image:DragBetweenTracksStereo.png|Example of resizing the channels of a stereo track]]

Changing the height of a track: Click and drag between the tracks.
 * [[image:DragBetweenTracksMono.png|Example of resizing a mono track]]

Working with Audio Tracks
For more information on working with audio tracks, see:
 * Audacity Selection: the special characteristics of audio selection and the tools Audacity provides to help you make exactly the selection you need
 * Audacity Tracks and Clips: all about clips - separate, movable regions of audio within a track
 * Sync-Locked Tracks: keeping a group of tracks in sync
 * Zooming: seeing what you need to see