What metaphors are used in Memoir by Mona Van Duyn?

In the fourth stanza, Van Duyn suggests that the separation of "sense and sound" is just one danger poetry faces. With the line "Detective Time takes his voiceprint, which ends behind bars," Van Duyn conjures the image of a police detective putting someone in jail. In this case, "Detective Time" seems to take its own voice prisoner. This line can be read metaphorically to mean that, as time passes, the unique experiences of those living in that time are permanently locked away. They are put behind bars and are thus unable to communicate with the outside world.