Set Trim selection MP3?

I want to trim trash (talk) out from the start and end of the MP3 music file.

The selection start and end for trimming can be set with mouse and with number values. However, these are sometimes quit clumsy to use.

I can easily hear, for example, when the talk begins after the music, but this is quite difficult to see from the graphical waveform track.

Is there any easy tool (key or button) to set the selection start and end points when listening the file ?

To repeat my two replies to you on feedback@…

Press [ on your keyboard when playing to set the start of the selection. Press ] on your keyboard when you hear the point for the end of the selection, which will then create the selection.

You can then use Cut (which removes the selection) or Trim (which removes everything except the selection) according to what you want to do. Trim and Cut both have buttons on Edit Toolbar (click the link to read about Edit Toolbar): .

If you have hidden Edit Toolbar, choose View > Toolbars > Edit Toolbar.

The only feature requests here that Audacity does not yet have would be:

  • Have buttons for the [ and ] keyboard shortcuts
  • Have [ and ] actually set markers in the waveform.

If you want to vote for either of those two additional features, please let us know.


CTRL + ALT + 8 or CTRL + ALT + 9 (assuming that is what you have to type to produce [ and ] ) will be interpreted by Audacity as that CTRL + ALT sequence rather than as [ and ].

I’ll add your vote for buttons for [ and ] .

Meantime the solution would be to open the Audacity Keyboard Preferences:

and change the keyboard bindings for “Left at Playback Position” and “Right at Playback Position” to a key you can press without using a modifier. You can choose anything that does not conflict with an existing shortcut.

So to explain how to make the change once you have the Keyboard Preferences open:

  1. In the “Category” drop-down, choose “Edit”
  2. Half way down the list, find “Left at Playback Position” and click on it to select it
  3. Click in the text box underneath the list then type the key you want to be the new shortcut for “Left at Playback Position”
  4. Press “Set”
  5. Repeat steps 1 to 4 for “Right at Playback Position” which is underneath “Left at Playback Position” in the list
  6. Click OK.