Just to get this out of my head, since it's a list that's been collecting for a bit, and I was reminded of all of them on Sunday.
- When you order food and get a number that they'll call you by when your lunch is ready, or put your name down for a table reservation, you can go off and read a book or talk to a friend or otherwise do something other than stand by the counter staring at the lips of the person with the microphone for the next however-many-minutes-it-will-take-your-food-to-be-prepared or your table to be cleared. (This is why I love restaurants that give you electronic coasters that will shake and flash to tell you that your table or your taco is ready.)
- At the airport, you will probably be notified when your flight is boarding, when your group within the flight is boarding, when your flight has been delayed, and whether your flight has moved to a different gate. You will not have to set your cell phone to vibrate several minutes before boarding time, look up, see nobody is boarding, then have to run with your luggage to the monitors posted in the hall to see that the display says your flight is an hour late and on the opposite side of a different terminal. (This is, however, better than having to ask the gate monitor or another passenger for help, which usually brings a withering "what, are you dumb? they just said that" stare before it brings the answer.)
- When clerks in a store call for your attention because you've dropped something or they've found what you were looking for, they call you once and you turn around. They don't call you multiple times in the middle of a crowded store then have to sprint forward and tap you on the shoulder while everybody else is watching.
- Your friends will never have to interrupt you mid-conversation and ask you to stop talking until a loud noise (or an enforced silent period) has passed; you'll be able to sense such things for yourself.
- You will never be mistaken for either rude or retarded for not responding to a stimuli you're not aware of.
- You can select a cell phone on the basis of price, aesthetics, features, and criteria other than "can I hear the speakerphone?" and "how emphatically does it vibrate in silent mode"? Similarly, you can choose ringtones based on actual musical appreciation rather than "which one contains the most frequencies within my hearing range?" (I had a phone for two glorious years where the optimal ringtone happened to be the opening of a Debussy piece. My current phone's optimal ringtone is this cheesy jazz-rock riff. Not bad, but... not Debussy.) Also, when your phone rings, you usually notice. Also, you can understand your own voicemail.
On the other hand...
- fire alarms and passing emergency vehicles are a painful experience
- fingernails on the blackboard make you wince
- ditto for brake screeches on the train
- if someone in the room next to you turns on the TV, you'll probably notice/be distracted/wake up