Boston’s WGBH added to the host of recent announcements of station layoffs today with the news that it will lay off 12 employees. The station has also frozen salaries for management and filling of vacant positions and reduced capital purchases. Membership revenue has held steady for the broadcaster, but corporate sponsorship has declined, said a spokeswoman. The Associated Employees of the Educational Foundation, WGBH’s in-house union, agreed to a restructuring of the network’s design department and to accept smaller wage increases next fiscal year. More in the Boston Herald.