The changing ways in which US listeners access radio is spilling over into audience measurement systems - and causing jitters among traditional broadcasters.

Broadcasters this week persuaded ratings provider Arbitron to delay reporting listening figures for satellite and internet radio until summer 2006 at earliest. The firm originally intended to include the figures in its fall 2005 survey.

The traditional lobby is concerned that audience-measurement changes could have a negative effect on their ratings and bottom line.

Under pressure form the National Association of Broadcasters' Local Radio Audience Measurement Committee and the Arbitron Radio Advisory Council, the information provider has revised its plan for including new diary instructions that tell radio survey participants to record listening to internet or satellite radio as well as FM and AM broadcasts.

Says the company's president of US media services, Owen Charlebois: "While we believe that modifying the instructions is the right thing to do from a research quality standpoint, Arbitron has decided to address more fully our customers' concerns with a limited test of the revised instructions in 25 markets in February 2006."

Comments Eric Ronning, who sells advertising on a network of online radio services: "In 1995 there was one form of radio in America — traditional AM and FM. Today the same 250 million Americans consider radio to be a derivative of four different things, and the only people who consider those separate entities are the owners because they need to, and advertisers because that's how they think. To the customer, it's radio, radio, radio."

Data sourced from; additional content by WARC staff