Lisping is a problem producing certain types of speech sounds. People who lisp have difficulty pronouncing fricative (hissing) sounds, such as s or z. They may substitute other sounds or distort these sounds. For example, in the sentence “I see my sister,” a person who lisps may substitute th for the s sounds and say “I thee my thithter.” Another person who lisps may distort the s into a whistling sound instead of the normal hiss.
Many children lisp when they first begin to speak. During normal speech development, most children master the hissing sounds long before school age. Sometimes a child’s speech development may be delayed for a variety of reasons. These reasons can include defects of the structures of the mouth, particularly the tongue, teeth, and palate. Children with hearing loss may lisp because they are unable to hear the hissing noise of fricatives, making it difficult for them to produce sounds they cannot hear. Almost all children lisp when they lose their primary front teeth (see Teeth).
When lisping results from structural problems, the structures usually must be corrected before the speaker can produce normal sounds. Speech-language pathologists (SLP’s), who are trained to treat speech and language disorders, teach people who lisp to speak correctly. SLP’s train individuals to recognize their own speech errors and then to form the sounds properly.
