Consonance
The echo of inner or end
Consonant sounds in some verses
Inner; as in the inner space
End, as in the end of the world
All of your recurrences are
Of letters other than vowels
The sounds of B, C, D, F, Gee
Or H, J, K, L, M, N, Pee
Q, R, S, T, V, W, X, Yee
And not forgetting letter Zee