www.arbitron.com/portable_people_meters/home.htmThe Portable People Meter System
The Portable People Meter (PPM) is a unique audience measurement system that tracks what consumers listen to on the radio, and what consumers watch on broadcast television, cable and satellite TV. The Portable People Meter is a mobile-phone-sized device that consumers wear throughout the day. It works by detecting identification codes that can be embedded in the audio portion of any transmission.
The Portable People Meter system consists of several components:
Encoder, which is installed at the programming or distribution source to insert an inaudible identification code into the audio stream;
Station monitor, which is installed at the programming source to ensure audio content is encoded properly;
Portable People Meter, which is worn by a consumer to detect and record the inaudible codes in the programming that the consumer is exposed to;
Base station, where each survey participant places the meter at the end of the day to recharge the battery and to send collected codes to a household collection device known as a "hub";
Portable recharger, which allows the PPM to store multiple days of media exposure data;
Household hub, which collects the codes from all the base stations in the survey household and transmits them to Arbitron via the telephone during the overnight hours.
Closely tied to the system's encoding/decoding technology is a patented respondent monitoring and feedback system designed to enhance survey participants' involvement with the study, lessening their burden and increasing their compliance with the Portable People Meter procedures.