Hi,
I have two suggestions depending on the structure of your recordings.
If all files have the same duration of silent parts at the beginning or at the end, you can use Praat. After you load all files to Praat you will select the convert - extract part command. It will reduce the file to the duration you choose and automatically create new files without editing the originals.
But if all files have different lengths you might wanna check Audacity. It has a built-in "truncate silence" command. It will cut all signals below the thresholds you can choose. Yet, please keep in mind that this will remove every silent part in your recordings.
Best,
Mustafa
Mustafa Yüksel, Ph.D.
Ankara Medipol University
Speech and Language Department