Trim or silence audio files in Logic Pro for Mac
With the Trim function in the Audio File Editor, you can remove areas of the audio file that are not selected. The function is, for example, useful for removing unimportant passages—such as silence—from the start and end of your audio files. You can also use the Trim function to remove portions of audio files that are not used by regions.
You can use the Silence command to set all amplitude values to 0, rather than removing (with Cut, Delete, or Trim) all data from the selected area of an audio file. This function is generally used to silence unwanted background noise in quiet passages.
Note: You cannot use the Trim or Silence functions on Apple Loops, surround files, or regions on tracks where Flex Pitch is turned on. If possible, bounce the region in place and make the edits to the resulting audio file.