I am using OpenEars version 0.913 on iOS 5.0 and it seems to work. I did make some changes to the AudioSessionManager however that might be making this possible specifically kAudioSessionProperty_OverrideCategoryMixWithOthers.
When it goes to background, iOS shows “fancy” red navigation bar as OpenEars keeps recording. I am using for continued iPod control, but an easy test is to fire local notifications on specific word/phrase recognition.
Greg