Audio Files space usage: noise versus silence

Question

Continuing on from my recent Disk Usage thoughts:
I've noticed that we arm a Logic track connected to a microphone, and begin recording the microphone from the very start of the song, even if the singer doesn't actually start singing until, say, bar 8.
So in the Audio Region, we see a flatline waveform for the first 8 bars before they start singing.
Turning my thoughts to disk space usage:
I've just read the section in the manual that says 1 minute of monophonic audio recorded at 16-bit dynamic resolution and 44.1 kHz frequency consumes 5 Mb of hard disk space.
Does 8 bars of silence use the same amount of disk space as 8 bars of singing? (I assume so - silence would be represented by, at 16-bit dynamic resolution, 16 digital zeros, whereas a sample of noise would 16 ones and zeros)
Moving on - let's assume that a singer has just sang on a track and I have an Audio Region that shows the first 16 bars as being silent. If I'm correct, using the scissors tool and removing the first 16 bars of the Audio Region does not affect the underlying audio file (my understanding: Audio Regions are simply pointers to an underlying file).
So how would I remove silence from the start of an underlying audio file? Do something in the Sampler (double clicking the Audio Region brings up something I think is called the Sampler)?

Answer 1

Does 8 bars of silence use the same amount of disk space as 8 bars of singing?
Yes, in this case.
Audio Regions are simply pointers to an underlying file).
Yes.
So how would I remove silence from the start of an underlying audio file?
Adjust the region to your liking, go to audio window, select unused, delete (just removes files or regions from session)
Then select the file and hit optimize or select the file's used regions and create new, then delete old later.
This is safer than optimizing the file, but ore steps.
J