In the case of an "oral" resonance disorder, the tongue sits too high in the front or back of the mouth. When the tongue is too far forward in the mouth, a type of 'baby voice' occurs, and a lisp may also result. Treatment involves practicing back vowels such as /a/ in "father", /o/ in "boat", and /u/ in "spoon", accompanied by back consonants like /k/ in "broke" and /g/ in "bog". When the tongue sits toward the back of the mouth, the voice sounds dull, and problems with articulation at the front of the mouth may also occur. Treatment focuses on front consonants such as /w/ in "where" or "work", /p/ in "pink", /b/ in "ball", /f/ in "laugh", /v/ in "leave", /l/ in "mail", and /th/ in "with" or "bath" coupled with high-front vowels like /i/ in "wheat", /I/ in "fit", /e/ in "pay", /E/ in "bet", and /ae/ in "slat". This type of resonance disorder is commonly seen in children with severe hearing impairment.