I will do some reading if a recorded file can be trimmed by time also

While searching for this ALE subject, I found this Italian video: https://www.youtube.com/watch?v=bZdw_YCLJqc

Looks Greek to me.

Besides, if you're familiar with Python, there's lot you can do with for example SciPy and the wavefile module to automate things.

Google for "scipy.io" +wavfile for example.