The following article was written by PROMPT Instructors Jennifer Moore, MS-CCC- SLP and Natalia Eva Mir MS-CCC-SLP for the PROMPT Institute Parent’s blog.
A lexicon is a set of approximately 10 target words that are worked on during therapy and throughout the day. The words are selected with 3 variables in mind: motor action (e.g. lip rounding), plane of movement (e.g. vertical; degree of openness of the mouth) and cognitivelinguistic concept (e.g. directional concepts; up, down.)
Before selecting a lexicon, a clinician must assess the client’s facial structure, facial muscle tone, phonation (voicing and airflow) and how the articulator’s (jaw, lips, tongue) musculature moves to produce a sound. This information will be used to complete the Systems Analysis Observation.
At this point, the clinician will also determine the client’s level of speech motor control; in other words, how developed are the required components to produce sounds? By answering this question, the clinician will identify strengths and weaknesses and will translate this data into the Motor Speech Hierarchy form. Speech requires the complex interaction of multiple motor skills. In order to produce more difficult sounds, a person must have already mastered the more basic motor movements. The Motor Speech Hierarchy is a visual representation of the levels of motor control that allows the clinician to identify what stage of development a child’s motor skills are at and then tailor their therapy to the proper level.
Once the clinician completes the System Analysis Observation and Motor Speech Hierarchy, the impaired motor actions are identified and treatment priorities are set. The clinician then selects motor-phoneme links (speech sounds) which correlate to the motor action the client needs to work on. For example, if the child is having difficulty with lip rounding, the phonemes /o/, /u/, and /sh/ may be selected because those sounds are produced with rounded lips.
The phonemes are then formed into words based on the plane of movement. Jaw opening is graded into four heights. Say these sounds and pay attention to your mouth opening wider as you go: ee (eat), ih (it), eh (bed), and ah (hot). The vertical plane of movement is opening/closing of the jaw to a wider position where “eh” and “ah” are produced. Think of the words “bed” and “mom”. Those words are on the vertical plane. Next, we have the horizontal plane. Think of the jaw heights where your mouth was more closed (“ee” and “ih”). Say the words “me” and “moo”. You are on the horizontal plane. Next we have anterior-posterior plane which is tongue movement. Think of the word “king” or “sack”. Those words require a lot of tongue movement. Lastly, some words cross planes of movement. For example, “mommy” is vertical and then horizontal. This is extremely hard for some kids as it requires a lot of motor control.
So when we are selecting the words, we look at motor action and plane of movement. If a child is having difficulty retracting their lips, we might target “ee” as that phoneme requires lips to retract. We would then select words on the horizontal plane of movement: see, me, tea, eat, bee. Lastly, we would take into consideration the child’s cognitive-linguistic domain by targeting which language concepts they need to work on. For example, if I want to incorporate actions, I would target “see” and “eat”. Maybe we are feeding a stuffed dog and each time we pull out a snack from the bag we say “see” and then label the item and then the dog can “eat” it. Only a few words are targeted during one activity and the activity is repetitive and predictable so we can facilitate spontaneous language and motor learning. Communicating with your clinician about which words that are targeted in therapy and why can help you reinforce words and concepts that are appropriate to work on at home