Clive Thompson has a great piece in wired magazine right now about how minutes talking on the phone have been on the decline since 2007. He points to the rise of other means of staying in touch, and the rising practice of text, email, or chat precursors to a call asking for permission. I would imagine that caller ID helps us to not answer calls that we don't want -- further reducing the volume of calls.
I remember a time a few years back when I would come out of an hour long meeting and have 5 to 7 new voicemail messages -- in just one hour! I had to clear out the box multiple times during a single day just to make sure callers were not presented with the voicemail box full message.
Now I have my voicemails delivered to my email box with caller ID info in the subject line. Most of them never get listened to and I also get to listen to the ones I want in the order I want (like email).
The one thing that I would like to add to Clive's post: I have more scheduled conference calls than ever before. This must map to the expanded geography of the people I am working with, but I find myself doing this even for people close by that I would have otherwise met in person.
I wonder if this is tracked in the survey referenced, because often we will have ten or more people on these calls for a full hour -- something we never would have done before. Also, does the tracking capture VOIP services like Skype and Google Voice -- there could be a rotation to that mode that is not visible to the phone data trackers.
Next up: Video calls. We are currently expanding our calling capabilities to have conference calls enhanced with video. So don't count the phone as dead just yet.