Lisp

A lisp is a speech impediment, historically also known as sigmatismStereotypically, people with a lisp are unable to pronounce sibilants (like the sound [s]), and replace them with interdentals (like the sound [θ]), though there are actually several kinds of lisp. The result is that the speech is unclear.Interdental lisping is produced when the tip of the tongue protrudes between the front teeth and "dentalised" lisping is produced when the tip of the tongue just touches the front teeth.The "lateral" lisp, where the /s/ and /z/ sounds are produced with air escaping over the sides of the tongue, is also called 'slushy ess' or a 'slushy lisp' due to the wet, spitty sound. In the "palatal lisp," the speaker attempts to make the sounds with the tongue in contact with the palate.