Editing Audio Files Graphically with Waveform Editing Tools

The File Editor includes waveform editing tools you can use to graphically edit the audio file in the waveform display.

About the Selection Tool

You can use the Selection tool to select part of an audio file, as described in Selecting All or Parts of an Audio File. When you open the File Editor, the pointer is a selection pointer (arrow). When you are done using another waveform editing tool, you can return the pointer to a selection pointer by clicking the Selection Tool button.

Figure. Toolbar showing Selection tool button selected.

About the Frequency Selection Tool

You can use the Frequency Selection tool to make selections in Frequency Spectrum View not just of time ranges but also of frequency ranges. You can copy, paste, and delete frequency selections as well as adjust the amplitude of frequency selections. For more information, see Viewing an Audio File in Frequency Spectrum View.

Using the Sample Edit Tool

You can graphically edit samples in the audio file using the Sample Edit tool. To use the Sample Edit tool, the waveform display must be zoomed in enough to see individual samples, which appear as small squares connected by a thin line.

Figure. Toolbar showing Sample Edit Tool button selected.
To edit samples using the Sample Edit tool
  1. Click the Sample Edit Tool button above the time display.

    The pointer becomes a Sample Edit pointer.

  2. Zoom in on the part of the waveform you want to edit.

    Figure. File Editor showing the Sample Edit tool in use.
  3. To graphically edit samples, do one of the following:

    • Drag a sample up or down to a new value.

    • Click directly above or below a sample.

    • Drag left or right to reshape the waveform.

You can also edit samples numerically in the waveform display.

To edit samples numerically
  1. Control-click a sample, then choose Set Value from the shortcut menu.

  2. In the dialog that appears, type a new value for the sample.

  3. Click OK.

Using the Audio Stretching Tool

You can time stretch all or part of an audio file to change the amount of time it occupies. When you stretch an audio file, the length of time changes but not the pitch (letting you fill dialogue, music, or other audio to a specific amount of time). For audio files with music or other repeating patterns, stretching the file changes the tempo of the music without changing the key. The range of the Audio Stretching tool is limited to between 25 percent to 400 percent of the length of the original audio.

Figure. Toolbar showing Audio Stretching Tool selected.
To graphically time stretch an audio file
  1. Click the Audio Stretching Tool button above the time display.

  2. In the waveform display, drag horizontally across the waveform to select the part you want to time stretch.

  3. Move the pointer over the right edge of the selection.

    The pointer becomes a Stretch pointer.

  4. Drag the right edge of the selection left to shorten the selected area, or drag it right to lengthen the selected area.

    Figure. File Editor showing the Audio Stretching tool in use.

Note: You can edit a graphically performed time stretch by double-clicking the action in the Actions tab. For more information about audio stretching, see Time Stretch.

When you shorten a selection of an audio file using the Audio Stretching tool in the File Editor, the empty part of the selection area is filled with ambient noise if an ambient noise print exists. If no ambient noise print exists, the empty part of the selection area is filled with silence. Shortening a selection using the Audio Stretching tool does not change the length of the audio file.

When you lengthen the selection using the Audio Stretching tool, any audio overlapped by the lengthened selection area is deleted. Lengthening the selection past the end of the file changes the length of the audio file.

If you hold down the Option key while dragging the selection with the Audio Stretching tool, the audio following the selection area ripples forward when you lengthen the selection and ripples backward when you shorten the selection. In both cases, using the Option key changes the length of the audio file.

Note: Stretching an audio file by a large amount can degrade the sound quality of the audio file.

For information about stretching an audio file numerically using the Process menu, see Time Stretch.

Using the Zoom Tool

You can zoom in on a specific part of the waveform display to make precise edits.

Figure. Toolbar showing Zoom Tool button selected.
To zoom in using the Zoom tool
  1. Click the Zoom Tool button above the time display.

    The pointer changes to a Zoom pointer.

  2. In the waveform display, do one of the following:

    • Click to zoom in.

    • Option-click to zoom out.

    • Drag horizontally to select the part of the waveform you want to zoom in on.

The waveform display zooms in on the selected area.

For information on other ways to zoom in and out in the waveform display, see Zooming In and Out in the File Editor.