Arbitron will defend its controversial Portable People Meter ratings measurement service at a congressional hearing on Wednesday, Dec. 2.

The House Oversight and Government Reform Committee, chaired by Rep. Edolphus Towns (D-NY), will "examine whether the PPM technology and methodology accurately measure radio audiences and whether PPM has a disproportionately negative impact on radio stations owned by minorities or targeted toward minority listeners," according to an announcement of the hearing on the committee's Web site.

Towns opened an inquiry into Arbitron's representation of minority listeners in June. The FCC launched a similar investigation earlier this year. Meanwhile, Univision Radio has refused to code its signals for PPM measurement in three markets.

Arbitron president/CEO Michael Skarzynski announced that his company "welcomes this opportunity to discuss the importance of electronic measurement, the effectiveness of the Portable People Meter service, the value of the data it produces, and our responsible approach to the deployment of the service." PPM data is used to set radio advertising rates in 25 markets, with another eight to be added by year's end.