If you've read our "Symbols" section, you know what desire tastes like. (And if you haven't, the get on over there now to find out.) In this section, we'll explore what it sounds like.
Just like that poor dude who's dying in stanza three, the sounds of success will ring out pretty clearly to you—if you know how to listen, that is. Here's a general hint that will help: pay attention to the echoes.
We have a ton of sonic repetition in this poem, in fact. We'll start with some alliteration:
Success is counted sweetest
By those who ne'er succeed.
To comprehend a nectar
Requires sorest need. (1-4)
We have just sixteen words in this first stanza, and yet four of them (that's 25% for you non-math majors) start with S. Three more start with N. And that's not even counting the additional four words that are sporting an S or an N somewhere in the middle or at the end ("counted," "those," "comprehend," and "Requires").
Between that alliteration and consonance, then, we're bombarded with sound echoes before we even get out of the first stanza. The same can be said for the last stanza, too:
As he defeated – dying –
On whose forbidden ear
The distant strains of triumph
Burst agonized and clear! (9-12)
Here, instead of S and N sounds, we have S's and D's. We also have a familiar end rhyme in "ear" and "clear." That long E sound also appears in "defeated" (9) and—hey, look at that—is a carryover from words above like "sweetest" (1), "succeed" (2), "need" (4), and "victory" (8). In the poetry biz, that's called assonance .
Now, to return to our earlier question: what's the sound of desire? What does it sound like to truly want something that you can never have? Well, it sounds like all this repetition. Think about it: it's a kind of torture not to be able to attain what you most desire, and that kind of thing is hard to put of your mind.
Dickinson knew that, which is why she snuck so many sound echoes into this compact space. The same sounds keep coming at us, again and again, just like your thoughts about that thing you've always wanted—success, riches, the high score on Ms. Pacman—bounce around in your head all day.