Staff at 666 ABC Radio are on tenterhooks awaiting an announcement by management of changes to program teams and schedules.

ABC Local Radio manager Andrea Ho refused to comment on Wednesday. It’s understood an announcement could come on Friday.

Staff are believed to be frustrated by delays in the announcement, with some suggesting the changes have been released in ‘‘dribs and drabs’’ but individuals are being ‘‘sworn to secrecy’’.

ABC managing director Mark Scott is expected to be in Canberra on Friday but it is understood it is to do with a television event rather than radio.

666 ABC Radio’s ratings have been falling steadily, most recently from 15.6 per cent of listeners earlier this year to 14.8 per cent in the latest results published in September, down from 19 per cent in the previous survey in late 2011.