Arbitron

Was the dominant provider of radio audience measurement in the United States prior to acquisition by Nielsen; now operates as Nielsen Audio.

Arbitron was the dominant radio audience-measurement company in the United States, tracing its roots to the American Research Bureau (ARB), founded in 1949. For decades it was the primary provider of radio ratings data, measuring listener audiences across hundreds of local markets and delivering syndicated research to broadcasters, advertisers, and agencies. Its methodology evolved from paper diaries to the Portable People Meter (PPM), a wearable device that passively detected encoded broadcast signals to capture actual listening behavior across radio, TV, and other audio sources. Arbitron's ratings data was central to the buying and selling of radio advertising, enabling stations to set ad rates and allowing media buyers to plan and evaluate campaigns. Its Area of Dominant Influence (ADI) concept, originally developed to define local television markets, became a foundational geographic framework in media planning. The company also provided qualitative audience research and software tools to help broadcasters and advertisers interpret and act on ratings data. Nielsen acquired Arbitron on September 30, 2013, integrating it into its broader audience-measurement portfolio. Nielsen subsequently retired the Arbitron brand and rebranded the operation as Nielsen Audio, consolidating radio measurement under the Nielsen umbrella alongside its television and digital measurement businesses. As a unit of Nielsen, the business continues to provide radio audience measurement services across the United States.