One of the most common patterns in sound is rhyme.  From childhood songs and tales to song lyrics, rhyme is instantly recognizable. Yet, rhyme, in its several variations, is only one of the ways to play with the sounds of words in a poem. 

Today many poets write in free verse, without metered rhyme schemes, so let’s look at other ways to add impact through word choices.  There are three other methods of manipulating the sound.  Alliteration is the repetition of the initial consonant.  Assonance is the repetition of the same medial (internal) vowel sound.  Consonance is the repetition of a consonant in the middle or end of a word.  Each of these can be used alone or work together to tie together the whole of a poem.

To illustrate how the sound of a poem can add impact, we will look at a selection from Anthem for Doomed Youth by the English poet Wilfred Owens.  Owens wrote while he served as a soldier during World War I.  One of the themes that run through several of his poems is the lament for the loss of his generation of young men to the battlefields.  This poem presents both the sound of a dirge and the sound of the battlefield through words chosen not only for meaning but also for the way they sound. 

What you might notice immediately is the poet’s use of end rhyme in the poem:

----------What passing-bells for those who die as cattle?
-------------------Only the monstrous anger of the guns
-------------------Only the stuttering rifles rapid rattle
 ---------Can patter out their hasty orisons.

These words also help set the “tone” or “sound” of the poem.  You might notice that the first line is a slow marching line, and the second one seems to pick up speed, with the third becoming even quicker.  One of the ways that the poet has shaped the lines has been through the use of consonance.  Listen to the {r} sounds as they begin to build in the second line and culminate in the alliteration of rifles/ rapid/rattle. As the sounds come closer and closer together the pace and tension of the lines grows until the reader is face to face (or ear to ear) with the sounds of the gun fire, which then fades as the {r} sounds become further apart again in the fourth line. 

The {t} and {d} sounds (which are formed the same way in the mouth, the only difference is that {d} is voiced) add to this effect throughout the poem. This is especially noticeable in the third line with stuttering/rapid/rattle. The poet has used to his advantage the sounds as we would reproduce them verbally (think of a child making “machine gun sounds”) and included these sounds in the words that he uses for meaning as well.  He could have written that the rifles’ “fire” or “bark” but he chose words that did double duty, working well both for meaning and for the echo of sound. 

With all of the sound play of the {r}, {t}, and {d}, the poem could have begun to sound frivolous. By utilizing assonance; the rounded sounds of the British {a} cattle/rattle/rapid/patter, the {uh-or schwa} sound the/monstrous/stuttering/ guns/orisons, and the long {o} for/those/only/only/orisons, the poet has kept the sounds of the poem serious. The over-all tone is the somber tone of one talking of the dead. In some ways, it is easier to manipulate the sounds of the vowels since these sounds repeat more commonly in the language and have a more subtle effect.  You might also notice that a single word can “participate” in multiple ways and can be included in different sound parings.  This is another way that the poet brings the poem together as a whole, with each piece contributing to the total desired effect. 

These ways of manipulating sound patterns can make quite a difference in a line.  You can use sound to reinforce meaning, to help “tie” together the sounds of an adjective/noun or a noun/verb combination, as RJ McCaffery has done in these lines from Girl on a Bike.  Listen for the hard {c/k} sound:

----------holding traffic so she can recover,
----------continue her slow cold climb
----------towards whatever has made her face
----------like mine, crease,

The sounds can also act as a bridge between sections of a poem and hold a poem together thematically.  Pug Marr’s  Danny’s Fire  begins:

----------Now whispers the flowertongue,
----------now hiss the splitwood and spits
----------the pine, now come the shouts

If you listen to the to the sounds of the words in this poem you will see that the fricative sounds, the  {s}, {sh}, and {f} reinforce the sense of fire. These would be the sounds that you would choose to transcribe the sounds of a fire.

----------wisping across the char. But clearest
----------of all, most certain of any, father's
----------shade moving slow above the ash,

You might also notice that Marr has used very open vowels the {a} sound in char/ash/father, which tonally resonate with each other.   The repetition of the sound brings a unity to the poem.

When considering your word choices in writing and revision, take the time to look at the sounds and the patterns in your own work.  At times, there are synonyms or similar words that can help your poem develop its own unique mood and tone.  It may be helpful to underline or highlight the occurrences of assonance or consonance in a rough poem to help you see what has developed in the first draft. From there you can determine in what ways it is possible to groom the 
sounds-patterns of the lines to bring a more unified and aurally pleasing resonance to your poem.