More than 188 million people in the US ages 12+ heard one or more network radio commercials during the December 2009 survey period, according to Arbitron’s most recent RADAR Report (Radar 103), reports MediaBuyerPlanner.

The Dial Global Contemporary Network was the top RADAR-rated radio network in the rankings, with an average rating of 3.1 and an average audience of 3.95 million listeners, Arbitron said. Dial Global Complete FM Network was the second-rated network, with an average rating of 3.1 and an average audience of 3.87 million listeners. Premiere Male Focus Network, Dial Global Adult Power and Westwood One Adults network rounded out the top five networks. Dial Global networks made up five of the top 10 RADAR-rated networks.

Since the September RADAR report, Westwood One’s new Adult Network debuted in the #5 slot among Adults 25-54 and was #12 in Adults 18-49. United Stations’ Impact Network moved up from #10 to #8 in 25-54s, and from No. 8 to No. 5 in 18-49s.

In terms of reach, the report indicated that radio reaches:

• 73.9% of those ages 12+
• 74.4% of those ages 18+
• 74.2% of those ages 35+
• 76% of those ages 18-49
• 76.4% of those ages 25-54

About the report: The RADAR 103 is the eighth RADAR report to incude both Arbitron PPM and diary respondents.