how can i make the macbook pro silent on startup? it always makes that tone upon startup that is so loud.

You need this nifty System Preference pane

http://www5e.biglobe.ne.jp/~arcana/StartupSound/BETA/index.en.html

The settings have to be changed in a Admin user, not a Standard user.

It can be done [Google: Debong my Mac], but is unwise to do so. The sound indicates that all systems are normal during the boot process. There might come a time when you need to reset the parameter RAM [PRAM] and in that case you will need to hear the sound multiple times so that you know when to release the keyboard command. If it your Mac has been 'debonged' then you will need to reverse that status in order to do the maintenance step. As annoying as it might be to you, it is best to leave it.

FYI... that "chime" you hear on startup means your Mac has passed it's diagnostics tests. It's important to be able to hear that chime.

Power-On Self-Test Beep Definition - Part 1

Power On Self-Test Beep Definition - Part 2

In addition to what everyone else has said, Apple recommends not turning off your machine (put it to sleep instead) unless you're going to be away from it for more than a couple days. I almost never restart, except for when I'm installing an update or something that requires a restart.

Simply turn down your speaker volume or mute, before turning off your mac and when you re-boot, the tone volume will be set at the lower level or of if muted.

The system pane I mentioned in my first post has a default setting of a lower volume, this way you can still hear the chime, just not as loud.

I checked the "mute" button in my picture below, but upon better thought will un-mute it the next time I'm in Admin User and just have the chime setting set at a low volume instead.