Pure-play Slacker Radio, at #5 in the "domestic" rankers for weekday 6am to 8pm listening, is one of the few operators to show a little growth from May. Its "average active sessions," roughly equivalent to broadcast radio's average quarter hour stat, is up from about 38,800 to 40,400. But Pandora (682,407 to 611,804), CBS Radio (144,001 to 139,818) Clear Channel (122,627 to 119,471) and Citadel Broadcasting (47,666 to 45,735) were all down or sideways. Cumulus Media drops from #12 in May to #15 in June, but Triton Digital says the company "inadvertently omitted log files that measure audience and time spent listening… therefore, not all of Cumulus' listening is captured in this report." Cumulus appears to drop from 9,974 average active sessions to 7,700. Pandora's drop is also notable, but there's a possible explanation there, too: "The code that measure audience and time spent listening was inadvertently omitted by Pandora in some versions of their mobile applications." A similar problem at Pandora was noted earlier this year, and Triton Digital says the latest omission "will affect June and July ranker data." Triton Digital now owns the former Ando Media operation, which uses the Webcast Metrics platform to do server-side measuring of internet listening. Check the June release of the Triton Digital Media Internet Audio rankers here.