A lisp is a speech impediment, historically also known as sigmatism. Stereotypically, 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.

The cause of a lisp can vary. In some instances, the cause is physiological, and the patient has some sort of deformity or medical condition which causes a lisp. For example, a child with swollen adenoids may tend to lisp, as will people who have recurring stuffy noses. Also, a lisp can be formed when the tongue is bruised or swollen. People with underbites and/or large tongues or tongue piercings may also lisp.

Treating lisps in children usually involves speech therapy treatments and is generally successful. Speech therapy sessions include a wide variety of activities and speech drills, though what specifically happens in any given session will depend upon many variables. The content of these sessions will be affected by the length of each therapy session (usually between a half hour and one hour), its location (whether at home, school or a private facility), the age of the child involved, whether the therapy session is private or involves a group, and the type of lisp that is being treated.

Russell Dominic Peters (born September 29, 1970) is a Canadian comedian, actor and disc jockey. He began performing in Toronto in 1989 and has been nominated for four Gemini Awards.

Russell Peters was born in Brampton, Ontario, Canada to Eric and Maureen Peters. His family is of Anglo-Indian ancestry and is Catholic. His father was born in Bombay, Maharashtra, India, and worked as a federal meat inspector; he is regularly mentioned and featured in his comedy work. His mother was born in Calcutta, West Bengal, India. He has an older brother named Clayton who was born in Calcutta. Russell attended Chinguacousy Secondary School for grades 9–10, and North Peel Secondary School for grades 11–12 in Brampton.

Peters began performing in Toronto in 1989. Peters' popularity extends to several countries. He has since also performed in the United Kingdom, United States, Australia, New Zealand, Ireland, Afghanistan, Sweden, South Africa, India, the Caribbean, Philippines, Vietnam, mainland China, Canada, Hong Kong, Sri Lanka, France, Singapore, United Arab Emirates, Bahrain, Jordan, Norway, Lebanon, Oman, Pakistan, Malaysia, and Trinidad among other places.