Adult. Ackermann shouldn't be recorded by people under 30, it is strange if teenagers record samples for characters who are OLD PEOPLE.....
I'm 24 but I can sound like an old person too. Actually it would be harder for me to act young pilots, so I rather do older officers.
Even
very old persons if needed (check the attachment, I act and sound like a 60 year old person without any edit). I'll record some more samples tommorrow.
Edit: I've found a miss-spelling in the script (red "is" and "r" are missing in the script):
This is The Earth Alliance Destroyer Achilles to Alexander, you are ordered to stand down by order of president Clark!
[attachment deleted by admin]