Lisps, or /s/ and /z/ distortions, can happen for a variety of reasons. In younger children, these distortions are expected, but once children reach 5 years old, these distortions are no longer age-appropriate. These sounds can be difficult for children to produce, and require 3 main factors for accuracy: tongue placement (behind the teeth), manner of production (fricative, or pushing air out continuously through a small opening), and voicing (voiceless for /s/, and voiced or vibrating vocal chords for /z/).
/s/ and /z/ lisps can negatively impact a child’s overall speech intelligibility, which can make communication difficult. At an age of rapid speech and language growth, children with lisps may find it challenging to communicate with peers and family.
The most common lisp types are interdental and lateral:
- Interdental: An interdental lisp occurs when a child’s tongue is placed between his teeth (similar to a /th/ sound), as opposed to staying behind his teeth. This placement is very common in younger children and is age-appropriate until around 5 years old. Interdental lisps can be treated through targeting tongue placement and working to keep a child’s tongue back behind his teeth.
- Lateral: A lateral lisp occurs when a child has difficulty with /s/ and /z/ manner of production. For these children, air flow is escaping out the sides of their mouth, as opposed to through the middle. This production is never age-appropriate, and therapy is necessary to modulate air flow to a more accurate placement.
Children with /s/ and /z/ lisps are at greater risk for distortions on /ch/ (church), /sh/ (shoe), and /dz/ (jump), and /jz/ (treasure). Should you have concerns about your child’s speech abilities and how a lisp may be impacting his intelligibility, a licensed speech-language pathologist can help!