I cannot figure out how to turn off the email notification sound without turning of the phone ringer. I am using K-9 email. The only thing I can find in the settings is to turn off all notification during "quiet time", which also includes the visual notifications. And if I go to Notifications in sound settings, I can only choose between the default sounds and the Zedge sounds that I have loaded. I don't see any option to choose no sound. I don't want to hear "Droid!" every few minutes.