Most sounds are grouped in pairs where one sound is made with the voice turned on and the other sound is voiceless.
The /s/ and /z/ are examples. Both are produced in the same way differing only in voicing (vibration of the vocal folds) with the /s/ being unvoiced (with your voice turned off) and the /z/ being voiced (with your voice turned on).
The sounds may be spelled with multiple letters several different ways including:
s as in sat, easy
c as in city
sc as in science
ss as in class
x as in box, xylophone
z as in zebra
Additionally, the /s/ and /z/ sounds are also grammatical markers. Plurals, possessives and noun-verb
agreement all require the use of the /s/ and /z/ sound. For example:
She walks (noun-verb agreement)
Two cats and two dogs (plurals)
Mom’s car (possessives)
Some reasons the /s/ and /z/ sound may be misarticulated may include:
Mouth Breathing
Allergies, nasal obstructions or habit may make it more comfortable for a person to breathe through their mouth instead of their nose. When this pattern is established, the mouth at rest remains open and the tongue tends to rest between the front teeth rather than the preferred position of closed lips with the tongue tip resting behind the alveolar ridge (the bumpy spot behind the upper front teeth).
Tongue Thrust
This often occurs in conjunction with mouth breathing problems. The person who displays a tongue thrust
usually swallows by pushing their tongue tip against their front teeth. The resting bite is often affected and
will be characterized as a frontal open bite.
Dental Problems
Sometimes a person with /s/ and /z/ problems will exhibit lateral open bite which is caused by spaces between the side teeth or a frontal open bite which results from spaces between the front teeth. Additionally the person may have a pronathic jaw, which places the root of the tongue too far forward in their mouth. This can lead to a frontal lisp.
Cleft Palate
Due to velopharyngeal insufficiencies, a person may have air leak through the nasal passages while saying the /s/ and /z/ sounds.
Functional Problems
This occurs when a person has immature speech, faulty learning, or other reasons that are unknown but may contribute to incorrect production of /s/ and /z/.
There are four types of lisps:
Frontal
This person typically substitutes a (th) sound for the /s/ or /z/ sound. The tongue is either too far forward against the teeth or between the teeth.
Lateral
The person distorts the /s/ and /z/ by producing the sounds with the air stream escaping from the sides of the mouth rather than through the front of the mouth. It’s sometimes referred to as “slushy speech.” Often it is
accompanied by a lateral open bite.
Nasal
This person has air escaping through the nasal passages when he or she is producing the /s/ and /z/ sounds.
It can be associated with a cleft palate or velopharyngeal insufficiency.
Occluded
The /t/ or /d/ sounds are substituted for the /s/ and /z/ sounds. This is usually a result of faulty
learning patterns or immature speech. It’s generally more common in younger children.
Sometimes children can learn to produce /s/ if they first start with a sound they can already correctly produce. Try the following hints for producing /s/:
- Smile! Move your tongue slightly forward and blow air down the middle of your tongue as you keep smiling.
- Shape the /s/ sound from (sh): Say the (sh) sound. Keep your tongue there and smile. Now move your tongue slightly forward while blowing some air down the middle of your tongue.
- Shape the /s/ sound from /l/: Say the /l/ sound. Now put your tongue in the position to make the /l/ sound and close your teeth a little. Lower the tip of your tongue and blow air down the middle of your tongue.
It’s recommended that students practice correcting their speech error at the isolation level for each sound. Move on to the syllable level when 80% mastery is achieved. After that, move to the word level once 80% mastery at the syllable level is reached. Next, move to the phrase level, then to short repetitive sentences, and finally to longer, more complex sentences as the student masters each level. Finally, reading stories aloud along with structured conversational activities will help the student move to the ultimate goal of correct production during conversational speech.