The real kicker is Nielsen could have partnered with cell phone companies to gather this kind of granular data but they're still stuck in the dinosaur age.
My Google Pixel phone tells me what I'm listening to all day long. Some of these songs were on a radio station I was streaming while others were playing on the supermarket P A. system when I went to buy groceries. Maybe one was heard coming from a car in the parking lot. The phone is always listening, yet somehow Nielsen makes people carry around inconvenient meters, or worse, fill out a diary like it's still 1985.