A while back when I first got my Evo, I looked into how to lower the dialer button volume but it didn't seem possible. It's good to have the audible feedback (along with haptic), but the entire office doesn't need to know that I'm dialing on my phone.

Now that the Evo has been around for a while, I did a new search and found a pretty good workaround. The dialer button volume is controlled by "System Volume," which isn't available in the stock Sense UI. But there's a free app that does allow you to control it:

Audio Manager

It appears that System Volume is set to max by default (7 out of 7 volume levels). I set it to 4/7 and now I have my ideal volume for the dialer buttons. But... If you use Google Navigation, it resets it back to 7/7 every time you open the Nav app. So you need another handy app, also free:

Volume Locker

This app analyzes all of your current volume settings and will preserve them. You can specify which volume sliders you want the locker to manage. Check the box next to "System Volume" and you've prevented Google Nav from changing it. I also lock the main ringer volume because I'm frequently accidentally changing it. The locker app notifies you whenever volume settings change, and it gives you a chance to accept it. If you ignore it, the locker app resets it back to what it was originally.


Note that "Audible selection" volume is also impacted by the System Volume slider, so if you turn the volume down, you may no longer hear the faint clicking noises from the audible selection. Rooted users can replace the stock click with a louder one to solve the problem.