The term dyslalia refers to a pronunciation or articulation disorder in which one or more phonemes are formed incorrectly, replaced by other phonemes or omitted. They can be seen as disorders in the phonetic or phonological area.

Phonetic disorders manifest themselves in such a way that a certain phoneme cannot be formed correctly due to limited oral motor skills. An example of this is sigmatism or the so-called lisp, in which the sound /s/ is formed incorrectly.

Disorders in the phonological area manifest themselves in such a way that one phoneme is replaced by another or partial phonemes are often omitted in phonetic combinations. The sounds that can often be formed separately are not used according to the rules of the language system. An example of this is the replacement of the sound /f/ with the sound /s/, so that /flag/ becomes the word /slag/.

It is often difficult to distinguish between the two areas. Occasionally, a mixed form can also occur, which is referred to as a phonetic-phonological disorder. In this case, a phoneme formation disorder occurs in parallel with a phoneme usage disorder.