Phonological Segments

In speech, a segment is any one of the discrete units that occur in a sequence of sounds, which can be broken down into phonemes, syllables or words in spoken language through a process called speech segmentation.

Psychologically, humans hear speech but interpret the segments of sound to formulate meaning from language. Linguist John Goldsmith has described these segments as "vertical slices" of the speech stream, forming a method in which the mind is able to interpret each uniquely as they relate to one another.

The distinction between hearing and perceiving is fundamental to understanding phonology. Though the concept may be hard to grasp, it essentially boils down to understanding that in speech segmentation, we break down the individual phonetic sounds that we hear into discrete segments. Take for instance the word "pen" — while we hear the collection of sounds that make up the word, we understand and interpret the three letters as unique segments "p-e-n."

Phonetic Segmentation

Another key difference between speech and phonetic segmentation, or phonology, is that speech refers to the full act of speaking and understanding the oral use of language while phonology refers to the rules that govern how we are able to interpret these utterances based on their segments.

Frank Parker and Kathryn Riley put it another way in "Linguistics for Non-Linguists" by saying that speech "refers to the physical or physiological phenomena, and phonology refers to mental or psychological phenomena." Basically, phonology works in the mechanics of how humans interpret language when spoken.

Andrew L. Sihler used eight English words to illustrate the idea that the articulatory figures of segments are easily demonstrable given "well-chosen examples" in his book "Language History: An Introduction." The words "cats, tacks, stack, cast, task, asked, sacked, and scat," he states, each contain "the same four, evidently discrete, components — in very crude phonetics, [s], [k], [t], and [æ]." In each of these words, the four separate components form what Sihler calls "complex articulations like [stæk]," which we are able to interpret as uniquely separated in terms of sound.

The Importance of Segmentation in Language Acquisition

Because the human brain develops an understanding of language early on in development, understanding the importance of segmental phonology in language acquisition that occurs in infancy. However, segmentation isn't the only thing that helps infants learn their first language, rhythm also plays a key role in understanding and acquiring a complex vocabulary.

In "Language Development From Speech Perception to First Words," George Hollich and Derek Houston describes "infant-directed speech" as "continuous with no clearly marked word boundaries," as is speech directed at adults. However, infants must still find meaning to new words, the infant "must find (or segment) them in fluent speech."

Interestingly, Hollich and Houston continue that studies show that infants under a year old are not fully able to segment all words from fluent speech, instead relying on predominant stress patterns and a sensitivity to the rhythm of their language to draw meaning fro fluent speech.

This means that infants are much more adept at understanding words with clear stress patterns like "doctor" and "candle" or parsing out meaning from language with a cadence than understanding less common stress patterns like "guitar" and "surprise" or interpreting a monotone speech.