Who I have the same questioned this topic

I updated my phone today to whatever system updates the phone said needed to be done (don't claim to be any type of expert or even half way droid literated...) The system version is 4.5.596 android version 2.3.3 if that is of any help. Right after I updated the phone, I started hearing the phone say "network extender". Now this started at work and the hospital I work in uses Verizon as the provider for all of their phones, so they might have a network extender in the hospital to boost their signal. I turned down the volume on the notifications, but I came home and it is continuing to say the same thing and I don't have a network extender. Why is it doing this? What does it mean? And how do I stop it without turning down the volume on all of my notifications?? Thanks for any help. C M