Dial pad tone

Can someone tell me how I turn off the dial number tones when dialing a phone number?

I've gone through setting after setting, turning down phone volume, keypad volume, and it's still annoyingly loud even when the phone is on vibrate or silent.

Thanks.

I need an app to do something as simple as muting the dial pad tone?

I can't wait for an Android and hurl this POStorm out the window.