Basically, add an option in the settings to turn off the notification sounds for all messages until turned back on. I would find this feature useful because I would like to turn my notifications off at work due to how many messages I frequently receive. Normally, I would turn my phone volume down, but I've lost several phones at work due to not being able to hear them ringing when calling from another phone to help locate it. So if a feature like this is added, I would be able to silence text notifications while leaving my phone ringing volume turned up.