I hear the soft, Lethéan song
Of many falling streams,
Winding oblivious, as they roll along,
Beneath the moonlight's rain of beams.
I hear the plaintive Nightingale
Singing with all his might,
Until the music seems to flood the vale
Afar with deluge-like delight.
A rose-bud, in his song's sweet rain,
Now bathes her drooping head,
Which so dissolves her beating heart of pain,
That she seems languishing as dead.
A cascade of sweet, mournful plaint,
He pours out through the grove,
As if his over-burthened heart would faint
With the sweet summer-heat of love.
But now the Nightingale is still—
A Spirit from above
Has drowned to silence each pellucid rill,
With the soft music of her love.
Her soft breath, like an odorous breeze,
Whispers to me to-night;
I am the soul of all such sounds as these—
It was the Voice of my Delight.
The above poem, "The Voice of My Delight," was dated June 8, 1840, by its author, Thomas Holley Chivers. The Georgia poet included it in his collection The Lost Pleiad (1845). Chivers often wrote on themes of love and of death (the latter particularly after the death of several of his children in their infancy). This poem, perhaps, combines the two. The theme of death is not the major one, however, but it is referenced in the first line with the "Lethéan song" — a reference to a river that flows in Hades, the Greek underworld.
Within the natural nocturnal landscape he describes, Chivers introduces us to a nightingale. This songbird in the poem is singing at night so strongly that it "floods" the scene. In fact, nightingales only sing at night when in search of a mate. The song is "plaintive," or sorrowful, perhaps because his love is dead. By the end of the poem, the nightingale has given up the search, presumably due to a lack of success. Further, the rose-bud hears the song as a "mournful plaint" (or "complaint"), and languishes near death because of it. In a foot-note, Chivers makes it known that he is referencing a work by the Persian poet Jami.
The poem, then, seems to be about an overburdened lover with no one to love, yet whose song of devotion impacts the world around it enough that it summons a spirit from the afterlife to the scene. That final image, the titular voice of delight, comes from a spirit representing the soul of the sounds heard throughout the poem, particularly the nightingale. The voice of Chivers's delight, then, might be (somewhat oddly) the spirit that recognizes those whose love is not returned.