Here's a report on NPR about a recent study on media use -
These are a few of the highlights:
"Most people average more than eight hours a day facing a screen of some sort — whether it be a television, computer, mobile phone or even GPS."
"The researchers were surprised to learn that younger baby boomers, aged 45 to 54, averaged roughly an hour more screen time than any other age group, including teenagers."
FWIW, my family has participated in Nielsen research. For over 10 years, we've participated in the shopping research they do - we scan everything with a barcode that we purchase and also report other purchases including medicine, clothing, etc. For about 2 years, we were also part of the media research. The adults in the family each had a monitor about the size of a pager that we were supposed to carry with us all the time we were awake and it would record our TV watching and radio listening. They discontinued us from the media research about 2 years ago, but we're still part of the shopping.