Tip or Blade for Alveolar Sounds
Tip elevation: Does your tongue tip lift to the top of your mouth, right behind your front teeth, to the little speed bumps of your alveolar ridge? The tip elevates and the right and left surface portions of the tongue push against the alveolar ridge causing a dip (narrow passageway) to form for airflow. The tip hoovers in space near the top of the mouth.
Blade elevation: Does your tongue tip point downward and lightly rest (stabilize) on the inside of your lower bottom teeth with the flat blade of your tongue contacting the alveolar ridge? The blade is the broad portion right behind the tongue tip. You can feel the blade resting on your alveolar ridge when your mouth is closed and your tongue is molded across the roof of your mouth. Blade productions may be considered mild distortions.
For typical speakers, fricative phoneme /s/, and its voiced cognate /z/, are produced at the alveolar ridge. The tongue is lifted forming a narrow constriction (tiny tunnel) for rapid airflow that causes friction. Air rushes quickly through a thin channel making a high frequency sibilant sound.
Sometimes it’s hard for children to control and balance the tongue to form and maintain a narrow opening. Speakers may develop any number of compensatory strategies for /s/ and /z/, such as changing tongue placement and airflow. Some individuals substitute a blade production, raising the broad section of the tongue with the tip contacting the lower teeth.
When treating /s/ and /z/, it’s beneficial to determine whether the client is producing all alveolar sounds with tongue tip elevation. In English /t/, /d/, /n/, /l/, and the tap sound, (middle consonant sound in “butter”, and “matter”, which is a fast sound that is something in between /t/ and /d/), are made with tip elevation.
We need to have the client’s mouth slightly open to see if their tongue tip elevates (rising movement) or lowers, or even if it tries to stick out, or move toward one side or the other. We need a window to view tongue movement. To make a window, you can use a flavored tongue depressor or the client’s pinky finger to keep the teeth slightly apart:
• Tongue depressor: Have the client lightly bite on the tongue depressor with one end at the molars and the other end sticking straight out of the client’s mouth.
• Pinky finger: Have the client place the very tip of their pinky finger on the back molars and lightly close their mouth (but don’t bite).
Shine a penlight flashlight into the client’s mouth. Have the client smile to increase the width of the window (so you can the sides of the mouth through the opening).
Check for tip elevation by having the client produce words for the alveolar consonants:
/t/: “ten”, “take, “talk”
/d/: “did”, “dig”, “dog”
/n/: “nine”, “net”, “neat”
/l/: “light”, “let”, “lock”
tap sound: “letter”, “kitty”
Remember that having your mouth open for a while can make you drool, so take quick breaks between words and have some tissues available. You can have the client watch their own productions in the mirror so that they can learn about their tongue patterns, e.g., “Let’s watch and see what your tongue likes to do for the /t/ sound. Look it lifted up high” (or “Look the tip went down”, or “Look it tried to stick out”).
Remember tongue placement is language-specific and it is important to review the phonetic inventory of every language to which a client has been exposed.
It helps to know whether or not all alveolar sounds are elevated before we ask for alveolar placement with tongue tip elevation for /s/ and /z/.