At the word level we look for particular patterns of errors that may provide information about underlying phonological processes. Extensive errors may reflect a poorly developed phonological system. They may also reflect underlying physiological deviations such as inappropriate modulation of voice onset or insufficient control of air expenditure.


The FSST4 is a test that is particularly valuable for assessment when such underlying deviations occur at this level.


We have found that describing errors to students using a distinctive feature approach with traditional notions of place, manner, and voicing is valuable, particularly as an instructional tool. For example, distinctive feature terminology is valuable when describing visual information on a speech spectrogram.


This first example illustrates the voicing feature.


The second example illustrates nasal vs. plosive manner. The use of technology and distinctive feature information is demonstrated more fully in the instruction section.


Older students tend to appreciate this descriptive information as it enhances their metacognitive understanding of speech production. Primarily for this reason, we have continued to use the Fisher-Logemann Test of Articulation Competence3 which has a scoring sheet that partitions errors into place, manner, and voicing categories. Identifying errors and discerning patterns and processes is a critical step in the assessment process.


Some speech samples are presented here to illustrate a variety of phonetic errors and the acoustic effects of poorly coordinated respiration, phonation, and articulation:

These words show difficulty managing voicing. Notice that phonemes are voiced in initial and medial position of words but devoiced in final position; notice also the extraneous voicing following glottal plosives.
These words show difficulty controlling air for fricative and plosive manner of production; notice also the difficulty controlling the onset/offset of voicing.
These words show nasal substitutions for initial sounds with different manners of production; notice correct production for /m/ and /n/.
These words show a substitution of a plosive manner of production for nasals and glides.
Notice how control of air expenditure and glottal and velar variations influence the production of these words.
Notice how vocal tension interferes with the coarticulatory aspects of speech production.
Notice the elevated pitch and resonance changes that occur with certain words; follow-up assessment should determine whether such changes are systematic or random.
Notice how first language phonology influences production.