Dear plutarch: In your scenario, "aaaaaaa" is exultifying, "zzzzzzzz" is stultifying. As a switch, I encountered a word new to me:
stull
n.
5prob. < Ger stolle, a post, orig., short, thick prop: for IE base see STILL16 any of several kinds of supports or frameworks used in mines to prevent cave-ins

Can you think of a stull useful in the tunnel of love? (Folks, remember I didn't start this. I am thinking of Love Canal, in New York, a site EPA was detoxifying.)