New York - Mar 18, 2002 - Two Philadelphia-area radio stations have begun encoding their Internet-streamed audio signals for the U.S. market trial of the Portable People Meter (PPM). WDEL-AM (1150) and WSTW-FM (93.7) are using separate Arbitron encoders to differentiate over-the-air audio from Internet-streamed audio. The distinct station identification codes - one for broadcast, one for the Internet - will allow the PPMs being carried by Philadelphia consumers to distinguish between exposure to the over-the-air signal and exposure to the Internet-streamed audio.

Arbitron endorses the streaming additions as a further demonstration of the concept that the PPM can accommodate the measurement of Webcast audiences.