When I was a kid, the first thing I would do on a Saturday morning was rush downstairs and watch Bugs Bunny cartoons. I loved how Bugs, Daffy and the gang played tricks on one another, told silly jokes and most of all how they talked. I remember how I burst into uncontrollable laughter when Daffy would spit when he spoke or how Sylvester said, "thuffering thuckatash." Today, when I hear, "I thaw a puthy cat outthide," I no longer laugh, because those words are usually coming from one of my clients.

Daffy and Sylvester demonstrate a speech disorder commonly known as a lisp. A lisp is a distorted or mispronunciation of the speech sounds. There are two basic types of lisps:

Frontal lisp: A frontal lisp is produced when the tongue pushes out between the front teeth when saying "s" and "z" and sounds like a "th." For example, "thoap" for "soap" or "houth" for "house."

Lateral lisp: A lateral lisp is produced when the tongue lays flat and protrudes between the teeth, causing air to escape into the cheeks rather than straight out of the mouth when producing "s," "z," "sh," "ch" and "j". The result is speech that is distorted, wet and "bubbly" sounding.

A lisp can occur with other sound substitutions or alone. When children exhibit a lisp alone, it usually does not affect their speech intelligibility – that is, how well you understand their speech. Nevertheless, a lisp sounds and looks different. School-aged children can feel embarrassed and become self-conscious about talking. They may not participate in classroom conversations. Caroline Bowen, Ph.D., speech-language pathologist says, "While there is usually little impact on intelligibility, the impact of a lisp on a child's 'image' can be quite powerful."

Television and movies often cast children who lisp because they "sound cute." A well-intentioned parent may disregard their child's lisp for the same reason. As the child grows, parents realize that this type of speech is no longer cute, especially if it starts to impact their written language. Some school-aged children have trouble spelling, because they may sound out words as they write and misinterpret the distorted "s" or "z" sound for a "th".

What Causes a Lisp?
There are many theories regarding how a lisp develops in a child including thumb sucking, long-term pacifier or bottle use and/or frequent upper respiratory illnesses. The placement of a thumb or pacifier in a child's mouth may cause the tongue to lay flat and/or protrude forward. Also, children may attempt to talk while a pacifier is in their mouths, causing reduced placement of the tongue for correct sound productions. Additionally, research has found that a child who has frequent upper respiratory infections may develop speech disorders, because the tongue lays flat in order for the child to breathe through the mouth (rather than the nose). "Alternatively, the child has learned to say a sound or sounds the wrong way, and the incorrect pronunciation has become a habit," says Bowen.

What to Do About a Lisp
If a child does not present with other disordered speech sounds and only appears to have a lisp, then what do you do? "The sound 's' is one of the most frequently occurring phonemes in conversational speech," says Jena Piekarski, M.A., CCC-SLP, school-based and private practice speech-language pathologist and mother of two. Developmentally, the "s" and "z" sounds are not "mastered" until 7 or 8 years old. However, in most situations children have acquired these sounds way before that time. Many children use these sounds clearly by 2 or 3 years of age.

"I usually wouldn't treat it (lisp) until at least the age of 4 to 4 1/2 unless the child's intelligibility is compromised, the family doesn't understand the child, they're getting frustrated or the sounds include more than just 's' and 'z'," says Piekarski.

Sharon Frank, M.A., CCC-SLP, private practice speech-language pathologist and mother of one recommends that, ".if the child is able to correctly say 's' in words (and maybe sentences) at age 4, I say wait and have them re-evaluated in one year, and in the meantime, I give parents suggestions on how to foster the 's' at home."

Most speech-language pathologists would agree that if you wait too long, a lisp could become a habit. "If the child is 5 years old and not saying 's' in conversation correctly, I would recommend speech therapy," says Frank. "It can be harder to correct a few years down the road, because the incorrect patterns have been more ingrained."

In regards to a lateral lisp, Frank recommends therapy as early as 4. "Lateral lisps are a whole different ball of wax . I don't think they're as likely to outgrow a lateral lisp and would recommend therapy for that as early as 4 years of age," says Frank.

Therapy for a lisp should be determined following an evaluation by a certified speech-language pathologist, who will also determine if the child is ready for treatment. To find a certified clinician in your area, contact the American Speech-Language-Hearing Association at 800-638-8255 or e-mail actioncenter@asha.org.

Saturday mornings are still filled with laughter as Sylvester desperately attempts to capture Tweety and Daffy tries to outsmart Bugs. Today, I try to look at their speech as entertainment rather than a very treatable communication disorder. I'm sure if I could get Daffy and Sylvester into treatment, I would be able to correct their lisps. The only problem would be dodging all the pie pans and exploding dynamite. So, as Porky Pig likes to say, "Th, th, th, that's all folks!" (Porky needs treatment too, but that's a whole different article.)

Want to see more?

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• Stuttering: When It Becomes a Problem
• Stuttering or Learning to Speak? How to Know the Difference
• Talk about it!