For a good example of a lateral lisp, check out this clip on YouTube of Sid the Sloth from the Ice Age movies:

This article outlines a case study of Rebecca (name has been changed for HIPAA) who was a 14-year-old girl with a lateral lisp. Although there are many different speech therapy approaches to treating a lateral lisp, this one will outline the method I used to help Rebecca fix her lateral lisp.

1. Take an Inventory

The first thing I did with Rebecca was collect a sample of which words and sounds caused her to lisp. I found that Rebecca had a lateral lisp on the following sounds in all word positions: /s/, /z/, “sh”, “ge” (like beige), “ch”, and “j”. I found she even lisped when trying to say these sounds by themselves, such as “sssss” or “shhhh”.

I highly recommend that when you’re collecting a sample of words, you try as many different words as possible. I also recommend you sample all of the different sounds that the child is having trouble with. You will often find that there is some context that the child is able to produce the sound correctly in. For example, perhaps the child can say the /s/ sound correctly when it is followed by the /o/ sound, like “soap.” or when it is found in a blend with /t/ at the end of the word, like “best”.

If you would like to download the word list I used (with over 400 words), click the link below:

For Rebecca, I spent two or three sessions looking for good productions but to no avail. Had I found a word that she could consistently produce correctly, I would have practiced that word over and over again to reinforce it and then start practicing similar words to expand her productions, such as practicing “vest”, “test”, and “rest”, if she was able to produce “best”.

2. Try Positional Cues

Since I was unable to come up with any good productions during the sample, I moved on to describing to Rebecca where she should put her tongue for the different sounds. We talked about how when she produced /s/, the air needed to flow over the front of the tongue instead of the sides. I had her place a drinking straw in front of her mouth right in the middle. When the air was flowing out the front, she would hear the air hit the straw. If not, there was no noise. We practiced the /s/ that way but she was not incredibly successful with this. I also had her try producing all of those sounds with both her tongue tip up and her tongue tip down to see if one was more successful. Again, it was not.

During this time, I was seeing the student once per week. We would try several different strategies per session and I would assign her to do the most successful ones as homework. After a week of her practicing the strategy, I could see if it was working or not. Unfortunately, none of these helped her produce the sounds correctly so we moved on, though they do work for some other children.

3. Use Other Sounds to Piggy Back

The next approach I tried with Rebecca was the one that ended up being the most helpful for her. For this step, I looked for other sounds that Rebecca was able to produce with forward air flow that were similar to the sounds she was having trouble with. For example, Rebecca could produce a very clear /t/ sound with forward air flow. This sound is very similar to /s/ because the tongue is in approximately the same position and the voice is turned off. The only difference is that /t/ is a short burst of air while /s/ has a continuous flow of air. I also found that Rebecca could produce a “th” sound with forward air flow. This sound is also similar to /s/ as it has continuous air flow and the voice is turned off. The only difference there is the position of the tongue (slightly forward for “th”).

The Exploding /t/ Strategy for Lateral Lisps:

I assigned Rebecca two assignments to practice at home for the upcoming week. The first one was to produce the /t/ but try to hold it out a little. The result was something like this:

“t…t…t…tsssss”

We called this “exploding /t/”. I instructed her to say /t/ three times and then on the fourth time, she was to make the /t/ explode into a longer sound. I didn’t tell her right away that this was producing the /s/ sound because I didn’t want to psych her out.

The next activity was to produce the “th” sound but then to pull the tongue back inside the mouth. I instructed her to start with “th” and then slowly pull the tongue back until it was behind the closed teeth. Again, I did not tell her that this produced the /s/ sound.

After the week of practice, I had her demonstrate both strategies for me. I found that the exploding /t/ activity allowed her to produce a beautiful /s/ sound whereas the backward “th” activity did not. We ditched the backward “th” and kept practicing the exploding /t/ until it was solid.

4. Practice Specific Words without Lateral Lisp

Now that we had established one context in which she could produce /s/ correctly (“tssss”), it was time to start putting that sound in some words. At this point, if I asked her to just say “sss” it was still lisped but if she added the /t/ at the beginning, she was more successful. For that reason, I chose words that ended with /ts/ for her to practice first. We did words like “bats”, “hats”, “boats”, “meats”, etc. I had her practice those with the “exploded /t/” at the end until she could do them correctly.

At this point, I showed her that she was actually producing an /s/ sound when she exploded her /t/. Once she could do the final /ts/ words, we worked on words with /ts/ in the middle of the word, like “pizza”, “artsy”, and “Betsy”. I had her practice words like this multiple times per day at home.

5. Expand to Other Words without Lateral Lisp

After practicing the /ts/ sound combination for several weeks, we began to work toward getting the /s/ separated from the /t/. We practiced by having her hold out the /s/ part of the /ts/ blend and then pause halfway through saying the /s/. I told her not to move her tongue during this pause. It sounded like this:

“tsssss….sssssss”

We gradually made the pause longer until she was able to simply start with the /s/ sound instead of always needing the /t/.

Once she could say “ssss” by itself, we worked on saying it in single words like “soup”, “messy”, and “brass”. We also worked on incorporating the /s/ into other blends like “sp”, “sk”, and “sl”.

6. Eliminating Lateral Lisp in Sentences (One Target Sound)

Now that Rebecca was able to produce /s/ in all word positions and in blends, we were ready to start saying the sound correctly in sentences. I would have her read or say a sentence and I would listen for all of the /s/ sounds. She would correct any that she missed. I sent home reading assignments that contained many /s/ sounds for her to practice.

Once we got to this point, Rebecca began remembering to produce the /s/ sound correctly in conversational speech as well. Some children may need extra reminders to begin doing this though.

7. Eliminate Lateral Lisp on Other Sounds

Once the child you’re working with is able to produce that first sound correctly in sentences and possibly conversation, you’ll want to go back and target one of the other sounds. Since Rebecca mastered /s/ first, we moved onto /z/ next. The /z/ sound is similar to /s/ in position and the way it’s made but the /z/ sound is produced with the voice on instead of off. To do this, you simply need to say the /s/ sound and then start your vocal cords buzzing. After a few attempts, Rebecca was able to do this with no problem. We then worked on putting that sound in single words and sentences as she was ready to move up.

When we were ready to work on the next sound, we chose “sh” because she was already starting to get this one on her own. We talked about how the air flow needed to continue forward just as it does for the /s/ and /z/. We were just beginning to work on this when summer break hit and Rebecca was unable to continue therapy. However, if we were to continue, I would simply continue improving the error sounds one at a time with a similar method to those described above.