Portable People Meter (PPM)

A wearable device used by Nielsen Audio panelists that detects inaudible codes in broadcasts to measure radio listening automatically.

By Brandon MinaCEO, BrandPilot AIUpdated November 2026

Short answer

A Portable People Meter (PPM) is a wearable device carried by Nielsen Audio panelists that detects inaudible codes embedded in broadcast audio. It automatically records which stations panelists are exposed to throughout the day, measuring radio listening passively rather than relying on handwritten diaries, and is used in larger US radio markets.