Bhaktivinoda Thakura tells us that there are three requirements for those who actually want to reach pure chanting: We must chant in the association of devotees who relish the holy name, we have to remove ourselves from all distractions, external and internal, and we must be steady and determined in our chanting.
Lectures from a disciple, Vol 1, p. 186, Minsk, 5.19.2002