The Science of Sound

Image courtesy of Sarah Dinu under licence

When considering the sound of a poem, it is useful to think of the human voice as a type of instrument. In fact, according to Lanier, “[t]he human voice is practically a reed-instrument of the hautboy class, the vocal chords being the two thin vibrating reeds, and the mouth and throat (buccal cavity) constituting the tube” (31). A person can create sound with their voice in the exact same way that they would create a sound on any reed instrument—by creating vibrations in the vocal chords and shaping those vibrations with their throat and mouth.

Lanier asserts that sounds may be studied in terms of four components: duration (how long a sound lasts), intensity (how loud a sound is), pitch (how high or low a sound is), and tone-color (the smaller sounds that combine to create the sound) (24). We can visualize these various components at work in the image of a guitar string. Once the string is plucked, it is possible to observe how long it vibrates (duration); the distance it moves back and forth, or its “excursion” (intensity); the speed at which it vibrates (pitch); and the additional smaller vibrations that combine with the “fundamental tone” to make up the composite tone (tone-color (26-30). To be clear, these four aspects are not limited to singing only. They absolutely apply to the human speaking voice as well, which is how I am using them in this instance—in terms of reciting poetry.

Rhymes and alliteration are formed by the tone-color of the sounds (40). Thinking back on the concept of the human voice as an instrument, “[i]t has been found that the ability of the ear to discriminate one vowel-sound from another, and one consonant-sound from another, is due to the fact that the vowels and consonants differ from each other in tone-color just as violin-tones differ from flute-tones, or from reed-tones, in tone-color” (31). Thus, we see an “a” printed on the page, and we know to adjust the muscles of the throat and mouth in such as way as to produce the particular tone-color that goes along with the symbol “a” (52).

Perrine writes that “rhythm works as an emotional stimulus and serves, when used skillfully, to heighten our attention and awareness to what is going on in a poem… by his choice of meter, and by his skillful use of variation within the metrical framework, the poet can adapt the sound of his verse to its content and thus make meter a powerful reinforcement of meaning” (155). In poetry, rhythm depends largely on duration, and according to Lanier the average rate of English utterance is approximately 180 words per minute (or 3 words per second) (Lanier 39, 61). Of course, this is just an average. In reality, there is no absolute time scale by which humans speak or read poetry; the primary rhythm is merely created by the relative time it takes to pronounce one syllable compared to another.

While these syllables operate rhythmically in relative time when spoken aloud, there is wild variation in their written depiction: “Each ‘sound,’ for the purposes of verse, is represented by one syllable… within the meaning of verse, ‘O’ is one sound, though represented by only a single letter; while ‘through’ is also but one verse-sound to the ear, though represented to the eye by seven letters, or signs of sound” (59). By listening to the recordings I gathered for this project (see “Conducting the Recordings” below), it’s clear that the primary rhythm of each reading is dependent on the individual reader. However, regardless of the number of words read per minute, the sounds relative to each other will always be the same; therefore, English words are primarily rhythmical (62), which is what allows for consistent meter in a poem.

The primary rhythm of words in English is naturally divided into secondary rhythm: “The tendency to arrange any primary units of rhythm [words] into groups, or secondary units of rhythm, is so strong in ordinary persons, that the imagination will even effect such a grouping when the sounds themselves do not present means for it” (64). In poetry (and, in some cases, in prose), tertiary rhythms come into play. One example of a “tertiary rhythm” is the recurrence of tone-color, represented with alliteration or rhyme. Another is the stress or emphasis speakers put on important words, or sounds of words—usually indicated by an increase of intensity and change in pitch—as a means of calling attention to them (83-4). Lanier goes on to define the fourth order of rhythm (the line), the fifth (the stanza), and the sixth (the poem as a whole) (88-96).

Finally, the volume at which the poem is read (obviously) depends on the intensity of the sound. “The English habit of uttering words is not only to utter them in primary rhythm…but to make a difference of intensity (of loudness or softness, the essential principle of all rhythmic “accent”), which renders one sound in each word prominent above every other sound in that word” (74). These adjustments in intensity vary widely from reader to reader; depending on how they interpret the lines, they may emphasize very different words, slightly altering the meaning of the lines.

Returning to the biological sending and receiving of sound, once the sounds are created with the voice, how do we hear and interpret these sounds? Consider this very rudimentary explanation: The vibrations created by the human voice travel through the air to the eardrum (or “tympanum”), then through a complex series of fluids and tiny bones, where they are then delivered to the brain and interpreted (25). We perceive the interpretation of these vibrations as sound, instinctively observing its duration, intensity, pitch, and tone-color. Through learning language, we learn how to properly decode these elements of sound to create or reinforce the semantics of the words.