3. Audio / Visual

• A comlink with frequency changing options was built into the trooper's helmet. The comlink used linked encoding sequences to rotate frequencies every few seconds while keeping all troopers in the unit synchronized. If a trooper's helmet was removed without the trooper first hitting the comlink's control stud (most likely found on the under-rim of the helmet), the frequency coding routine was automatically deleted from that helmet.
• The Comtech Series IV helmet speaker used three-phase sonic filtering for clear sound (For troopers, it was connected to the audio pickup).
• It also had a vocoder for talking to non-Stormtroopers.
• Video recorders were included in some helmets.