I love it when customers come in, and when I ask what I can do for them, they lean in close and sort of whisper, "I just have a deposit."
Why are you whispering? Is it a secret deposit? You don't want the stranger standing five feet behind you in line to know that you've had cash this whole time and now you're putting it in a secure place. What's he gonna think, "Darn, I should have robbed her when I had the chance!"
No, that's not what's going through that person's mind. Unless it's an actual bank robber, and those occasions are rare at best. All that person is thinking is they've got their own business to do and they want you to hurry with yours.
This isn't a library. There are no people sitting around studying for mid-terms. No one is going to shush you if you use your regular inside voice to say you have a deposit or a payment or you'd like to cash a check.
Now, I wouldn't go to the other extreme and shout about your business either. Though, how funny would it be if someone just strolled up to the counter and proudly announced that they wanted to deposit a $183.10 check. I'm picturing Steve Martin doing this. And he's really excited and stuck up about it.