Speech production is a complex process of coordinating respiration, phonation, articulator placement, and nasal/pharyngeal/oral resonance to create the particular sounds recognized within a language as being meaningful.

    Producing speech sounds involves generating enough breath support to vibrate the vocal cords and then directing the sound produced by the vocal cords into the mouth and nose to be shaped. Shaping occurs by moving the tongue, cheeks, palate and lips into specific positions to produce a specific sound. For example, when producing the /n/ sound, air is exhaled in order to make the vocal cords vibrate while the lips close and soft palate opens. This forces the sound into the nasal cavity and out the nose. For /p/, the air is directed into the mouth (the palate closes off the nose) and the lips "pop" together to form the sound.

    In general, speech sound production errors are classified into 2 main categories: 

    The American Speech-Language and Hearing Association (ASHA) also categorizes disorders of voice and fluency as speech disorders. 
    In addition to the above mentioned areas, some children may exhibit difficulties with neuro-motor sequencing of speech sounds.  This is referred to as Apraxia of speech.