Yeah, while 5 minutes is way too much in my opinion, 5 seconds is much too short, I'd say 30 seconds to 2 minutes depending on how close you were to 066 or for how long you were close to him. However, I do still think a continual ringing might be rather annoying, perhaps a subtle, intermittent one, that plays for 30 second intervals, over the course of 5 minutes.