This rotated, but otherwise unretouched screen capture from StreamingRadioGuide.com shows the actual, calculated listenership for Rush Limbaugh, with the oldest dates on the left.
The Portable People Meter is "...worn like a pager, and detects hidden audio tones within a station or network's audio stream, logging each time it finds such a signal. It has proved to be much more accurate than the old handwritten logs or wired meters, and is immune to forgetful test subjects."
Please note: this diary contained errors. For a more recent evaluation, please see: