As anyone who travels frequently by bus, plane or train can tell you, important service announcements are best when they're utterly incomprehensible: being able to hear and understand that your gate has changed or that you left your phone at a security checkpoint denies people of that rush of adrenaline and feeling of vitriol that makes getting from point A to B such a rewarding experience.
If you've ever wondered how the men and women behind the microphone are able to ensure that no one EVER has a clue of what in the hell they're saying, you'll want to head on over to Paste Magazine – they've got the goods on how New York City subway conductors warm up their voices before going on shift. It's all useful stuff. Knowing this one handy hint alone could help speed you on your way to a new career in the transportation industry:
When used correctly, your tongue can make any vital service change announcement sound like it's dialogue in a movie where an explosion just happened and everyone's ears are ringing. As a warm up exercise, try to keep your tongue completely still, hovering in the middle of your mouth. Now try announcing, "F trains are now running along the A line." With your tongue motionless, you won't be able to articulate a single consonant sound. Your passengers will have no idea what the hell is going on. Feel free to also try this exercise while holding your tongue between two of your fingers. Try saying things your passengers definitely need to hear, such as, "Express trains are now running along the local track." You'll find it impossible to string together coherent syllables, which means the exercise is working!
OK, it's all tongue-in-cheek (another fine way of speaking if you want to keep people from understanding what you're saying) but I'll be damned if it doesn't smack of truth.