If I call the number, it rings 6 or 7 times before James Earl Jones picks up and tells me that the Verizon user has not set up their voicemail yet. No way to identify the caller based on voicemail message.

Rob, it may very well be some sort of machine waiting for a connect noise. I would hook up a listening fax and listening modem in a heart beat, but the victimized line is my primary house phone which is also used by my sisters business. I can't get in it's way. But, hm...... at night....... turn the ringer off, put a fax or computer on it......