Why does my phone say "Verizon Wireless" when I receive a phone call?
These voices were the result of having the so-called "Roaming tone" enabled in the Sound settings.

Strangely, the description of this setting is:


  Roaming tone
  Set notification tone informing the status of cellular service


After disabling this option, she no longer speaks to me when I receive a phone call or turn on/off airplane mode.

Though I have no idea how a speaking voice is considered a "notification tone"...