How are hearing and vision connected?

Hearing is vision looked at from a slightly different point of view. 

When any faculty is in motion—is being exercised, the spirit hears it, and it is to him the highest and truest form of music when the faculty is at rest, then the eye sees it, and it is to him the highest form of art—true painting and true sculpture. Hearing is also not confined to the present—the past back to the soul’s first dwelling in flesh is ‘audible’ to the spirit ear. Further back than that in the soul’s history remains to be unfolded in the higher spheres—the seventh chiefly.