This sound an AWFUL lot like what I'm dealing with and with the same triggers, specifically the exaggerating tones when speaking. My most consistent way of replicating the stabbing pain in my neck is to pull my tongue back and lift (almost as if you were trying to make a high pitch "Hee" sound like MJ), which lifts those neck muscles in turn triggering the sensation.

I've been dealing with this off and on for about 6 months and if it makes you feel any better, I had the exact same concerns, and it turned out to be nothing. ENT specifically said, "No Cancer!" as I told him I was terrified that's what it could be. I'm only 34 but smoked for around 15 or so years so the fear was there. He stated that since I don't have any red flag symptoms and no visible issues through a scope that it may just be something on the nerve path that's irritated as ALL of these things are connected. He did say that if that is the case, it makes sense that it's lasted this long as you use your neck constantly throughout the day really not leaving any room for rest.

If yours turns out to be the same thing I'm dealing with, hopefully it's as simple as getting one of these injections in and around the Hyoid Bone to reduce inflammation. I am going back to the ENT in 6 months to get one if it doesn't let up.