Like Graham Kennedy, Doyle specialised in subtly (or blatantly) undercutting the "straight" presentation of such stock segments, and he often veered off on tangents that he found funny or diverting, or introduced ideas which he thought might be likely to get a "rise" from his guest. One memorable thread was his long-running obsession with the source of a supposed "mystery noise" that was reputedly disturbing patrons in the Opera House Concert Hall, and he regularly badgered long-suffering Opera House publicist David Brown for an explanation. The inadequacy of the women's toilets were also a frequent subject of discussion, or more correctly, interrogation, and the "whats on at the Opera House" segments stretched from around 10 minutes to a whole half-hour, through most of which David Brown's characteristic laugh was a highlight.