And now, my friends, please to excuse My lisping and my stammers; I, for this once, have done my best, And so--I'll make my manners.
These are all classified as lisping and include excessive pressure by the tongue against the teeth, the tongue held too far back along the midline of the palate, and a "substitute hiss" produced in the throat or larynx.
Jamie Oliver and his lisping, mockney screen presence has carried him from speech impediment obscurity, to movie star celebrity status.
Lisping is a speech disorder characterized by the inability to correctly pronounce the sounds of s or z, known as the sibilant consonants.
Lisping is, therefore, sometimes called a developmental phonetic disorder.