Foolish artist, why must you sketch my face
And hound a goddess eyes cannot detect?
I am the daughter born of Speech and Space,
Babble's mother, a voiceless intellect.
I snatch a word before it disappears
Then mimic mindlessly what I have found.
I am Echo--I live within your ears.
If you believe you can paint me, paint sound.

AM Juster

http://www.poemhunter.com/poem/to-a-painting-of-echo/