Apple Soundtrack Pro - Manual (Page 166)

166 Chapter 7 Working in the Waveform Editor
Time Stretch
You can time stretch an audio file or selection. When you time stretch an audio file, you
change the duration (length) of the file without changing the frequency (pitch) of the
file. For example, for a file containing music, the tempo of the music is changed, but
not the pitch. When you time stretch an audio file, you can choose the format for time
values you enter.
To time stretch an audio file:
1 Select the part of the file you want to time stretch (it can be the entire file).
2 Choose Process > Time Stretch.
The Time Stretch sheet appears.
3 In the Time Stretch sheet, choose the format for setting the amount to time stretch the
file from the Format pop-up menu.
4 In the “Length of selection” value slider, do one of the following:
 Click the left arrow to shorten the length, or click the right arrow to increase the
length.
 Click the center of the value slider, then drag the slider that appears left or right to
change the length.
 Click the value in the value slider, then type a new value.
5 Click OK.
Adding Ambient Noise
When editing an audio file, you may want to remove some sounds from the file while
preserving the room tone or other ambient background noise in the file.
Soundtrack Pro features two commands, Set Ambient Noise Print and Apply Ambient
Noise, that you can use together to add ambience to the file.
Set Ambient Noise Print
The Set Ambient Noise Print command lets you copy part of an audio file containing
only ambient noise that you want to add to another part of the file (or another file).
To copy part of an audio file to ambient noise:
1 In the waveform display, select the part of the audio file containing only ambient noise.
2 Choose Process > Set Ambient Noise Print.
The ambient noise is stored in a special buffer separate from the Clipboard, and is
saved to the project.