I've never actually come into contact with a PPM device, a Portable People Meter, used to measure radio ratings. But I've read that they can be fairly clunky "pager" like devices that need access to an Internet docking station. 

Now they've come out with some new "wearable" and far slicker PPM devices that should make it easier to follow the chosen "rater" around for a much better picture of what he or she is listening to. They're being rolled out this year in the U.S. and - if they work as advertised - I can't believe Canada will be far behind.

You can see and read about the next generation of these devices here.