Frontal & Lateral Lisps

Frontal and lateral lisps are specific types of speech sound distortions affecting sibilant sounds, most notably /s/ and /z/. A frontal lisp (also called an interdental lisp) occurs when the tongue protrudes between the front teeth during production of these sounds, causing them to sound like "th." A lateral lisp occurs when airflow is directed over the sides of the tongue rather than down the midline, producing a "slushy" or wet-sounding quality.

Frontal lisps are considered developmentally appropriate in young children up to approximately age four and a half, but should resolve naturally. Lateral lisps, however, are never considered part of typical development and warrant intervention when identified. Both types of lisps can persist into adulthood if not treated and may affect self-confidence and social interactions.

Speech-language pathologists use a variety of techniques to correct lisps, including teaching correct tongue placement, shaping from other sounds the child can produce accurately, and using visual, tactile, and auditory feedback to establish and generalize the correct production. With consistent therapy and practice, lisps respond very well to treatment.