Cubicle tunes.

It's still not as prevalent as water cooler gossip and football pools, but listening to online radio is moving up the list of office goof-off opportunities.

Comscore Networks and Arbitron recently released numbers from a joint study showing that the average daytime audience for online radio networks topped 1 million people during the month of June. All together, more than 6 million different people, age 12 and older, tuned into the six networks in the study.

A significant share of this daytime audience listens to the radio at work. During summers and holidays the online audience declines, thanks to fewer people at their desks. Also, listening spikes during the 10 a.m. to 3 p.m. period, reaching a cumulative audience of almost 3.3 million.

"People are definitely listening to online at the Office," said Diane Williams, manager of online radio ratings at Arbitron. "When people think of traditional FM radio, they think of the morning and afternoon drives as the peak periods, but it's midday for online radio."

Networks in the study included ESPN Radio, owned by Burbank-based Walt Disney Co.; Live365, which has a large Hollywood office; Microsoft's MSN Radio; and Clear Channel Online Music & Radio. The largest networks by audience were Yahoo Music (average of 1.5 million listeners) and AOL Radio Network (1.1 million), owned by Time Warner Inc.

At the five networks measured in both 2005 and 2006, audience increased 38 percent. The data come from a panel of online listeners provided by Comscore who load a program onto their computer. The program tracks online listening and sends the information to Arbitron.

Williams said the methodology focuses on the original source of radio programming, and thus provides no geographically specific data. Listeners can access ESPN programs, for example, at the ESPN site or at the sites of dozens of radio stations around the country that simulcast the signal. The study only captures those who plug into ESPN directly, as a gauge to measure advertising at the ESPN site.