what does the poem "the voice you hear" mean?

I'm assuming you are referring to "The Voice You Hear When
You Read Silently" by Thomas Lux. If this is not the poem to which you are referring,
please post again with a more complete identification of the work about which you are
asking.

"The Voice You Hear When You Read Silently" is
illustrating the ways in which we all add our own personal experiences and meanings to
the written words we read on the page. Because of the background knowledge and events in
our lives, certain words (such as "barn" in the poem) carry added significance when we
read them. Those added meanings will be different for every reader, even when they are
reading the exact same text, since the experiences creating those meanings will be
unique.