Do You Have a Lisp?

When people hear the word “lisp,” they often have a pretty specific sound in mind. Maybe an S sounds a little like “th.” Or maybe it has a slushy quality. You may have wondered whether you have a lisp yourself. Maybe someone pointed out your S when you were younger. Maybe you had some speech therapy as a child.

There are several ways to produce an S, and small differences in tongue position or airflow can change the way it sounds. For adults, the more useful question is often not “Do I have a lisp?” but “Do I like the way my S sounds?” If the answer is no, speech therapy can help.

S is a voiceless fricative. “Voiceless” means that your vocal folds are not vibrating when you produce it, it’s all done with focused airflow. “Fricative” refers to what is happening with the airflow. Instead of completely stopping the air, you create a narrow passage in the midline of your tongue and allow air to pass through it. The friction created by that airflow gives S its characteristic sound. A clear S requires a fairly precise combination of tongue position and airflow. The tongue creates a narrow channel for the air. The sides of the tongue help contain the airflow, while a groove forms through the middle. The air travels forward through that groove and exits the mouth in a focused stream. You can think of it as creating a little pathway for the air. 

When working on S, one thing an SLP may look at is what the tip of your tongue is doing. Some people are “tippers”. Others are “dippers”. Both can produce a clear S.

With a tipper, the tongue tip is raised toward the area just behind the upper front teeth. It may hover near or lightly contact the alveolar ridge, which is the small ridge just behind your upper front teeth. With a dipper, the tongue tip is lowered, usually resting behind or near the lower front teeth. In both positions, the tongue still needs to create an effective central groove for the airflow.

So which one is “correct”? Both actually! There is not one universal tongue position that every person needs to use for S. Your anatomy, tongue movement, existing habits, and comfort can all influence which position works best. Some people find that the “dipper” position gives them better control. Others find that raising the tongue tip feels easier and more accessible. This can be an important part of therapy. If you have worked on your S before without much success, trying a different tongue position may give you another way into the sound. The goal is to find a position that produces a clear, consistent S with forward airflow.

“Lisp” is a general term used to describe certain differences in the way S is produced. There are several types of S distortions, and they do not all sound the same. One familiar pattern is an interdental lisp. With an interdental lisp, the tongue comes too far forward and moves between or against the front teeth. This can make S sound more like “th” For example, “sun” may sound closer to “thun”. Another type is a lateral lisp, which has a very different sound.

A lateral S, sometimes called a lateral lisp, happens when the airflow escapes over the side or sides of the tongue instead of travelling forward through the middle. This is often the S people describe as “slushy”. With a typical clear S, the sides of the tongue help contain the air while the middle of the tongue creates a pathway. With a lateral S, the air escapes out the sides toward the cheeks. The problem is not necessarily that there is too much air. The problem is that the air is going in the wrong direction.

Not every unusual S is necessarily a lisp. Sometimes an S sounds unusually intense or prominent because the speaker is using too much air pressure/airflow. Some clinicians refer to this as a “hot S.” A hot S is different from a lateral S. With a lateral S, the main issue is often where the air is going. With a hot S, the airflow may already be travelling in the right direction. There may simply be too much pressure behind the sound. People with this type of S may describe it as a “lisp” and be seeking therapy because it bothers them.

That distinction between direction of air and pressure of air matters because the therapy approach can be different. Someone with a lateral S may need to work on tongue shape and establishing central airflow. Someone with a hot S may already have a workable tongue position and instead need to find a more comfortable amount of airflow and pressure. You do not want to automatically treat every unusual S as a tongue-placement problem.

There is not always one simple reason. Speech requires extremely precise coordination between the tongue, jaw, teeth, lips, and airflow. Over time, your brain learns patterns for the sounds you use. Most of the time, you are not consciously thinking about where your tongue is when you say words like “sun” or “seven”. Your speech system has learned the motor pathway for the movement and simply runs it. Some people develop a particular S pattern during childhood and continue using it into adulthood. In other cases, things such as dental structure or jaw movement may influence the way the sound is produced. Sometimes there is no obvious reason why someone developed a particular S.

In one case, a client came to me because they thought they have developed a lisp from getting an “Invisalign” teeth aligner. The truth is, this was probably only temporary since the air was no longer passing through their teeth, and was being blocked by the aligner. But since this would only be temporary it was not necessarily worth shifting their S around at that point in time.

Yes. One of the most common misconceptions about speech therapy is that it is mainly for children. Adults can learn new speech patterns too. The process is similar to learning any other motor skill. First, you need to understand what you are doing. Then you need to find a movement pattern that works better for you. Finally, you need enough practice for that new pattern to become increasingly automatic.

If you have been producing S the same way for many years, a new S may feel strange at first, it may even feel wrong. But the truth is often that the new sound may simply be unfamiliar. I usually tell clients that initial practice should feel a bit stilted and uncomfortable, because that means you are doing something outside your usual patterns. If practice immediately feels familiar you are probably practicing your default. With practice, that new movement can become more familiar and eventually require much less thought.

Speech therapy for an S difference is usually very practical. The first step is figuring out what is happening. An SLP may look at your tongue position, jaw movement, airflow, and the sound itself. You may use a mirror or other visual feedback to help you understand what your tongue is doing. You may also experiment with different tongue positions. This is where trying both “dipper” and “tipper” positions can be useful. Sometimes a small change in tongue position makes the sound much easier to produce. Once you find a tongue position that works, therapy focuses on making that movement more consistent.

One technique that can sometimes help is using T to establish the tongue position needed for S. You might practise a series of T sounds and gradually “shape it” and extend the airflow into S:

T-T-T-TSSSSSS

From there, you can begin practising S in words. The exact approach depends on the individual. There is no single exercise that works for every type of S difference.

If your jaw is moving to the side, for example, therapy may include strategies to help stabilize the jaw while you develop a new tongue movement. If you have a lateral S, the focus may be on establishing central airflow and preventing air from escaping over the sides of the tongue. If you have a hot S, the focus may instead be on reducing excessive pressure and finding a more efficient amount of airflow. The therapy should match the reason your S sounds the way it does.

Producing a clear S once in a therapy session is only the beginning. The real goal is to use it in everyday speech. You probably do not want to spend the rest of your life thinking, “Where is my tongue?” every time you say an S. This is why therapy typically moves through different levels of difficulty. You may start with S by itself, then move into words, phrases, and sentences. From there, practice can progress into reading and eventually spontaneous conversation. For adults, that last step is especially important. You may need to use S while introducing yourself, participating in meetings, giving presentations, or speaking on the phone. The goal is for the new movement pattern to become increasingly automatic. Eventually, you should be able to focus on what you are saying rather than how your tongue is positioned.

There is no universal timeline. Some adults notice a difference fairly quickly once they find an effective tongue position and airflow pattern. For others, it takes several sessions or several weeks of practice for the new movement to become consistent. The type of S difference matters, and how consistently you practise. Short, regular practice is generally more useful than doing one long practice session every couple of weeks. It can also be helpful to record yourself from time to time. Your own S can sound surprisingly different when you hear it played back, and recordings can make gradual changes easier to notice.

That part is up to you. A lisp is not automatically a problem that needs to be corrected. Speech differences are part of normal human variation, and many people communicate perfectly well without changing their S. Speech therapy can be useful when you want to make a change. Maybe you have been self-conscious about your S since childhood. Maybe you have started noticing it more in professional settings, like you hear yourself on a recording and think, “I wish my S sounded different.” Those are all reasonable reasons to explore therapy.

It is also important to remember that there is no “perfect” S sound. First off, it is a sound made with aperiodic noise (e.g. it is irregular and noisy, like tv static). One person’s S is not exactly like another’s. I usually say to think of speech sounds as existing not as a bullseye on a target but sitting in an irregular blob, everything inside the blob is “S” and everything outside of it is “Not S”. The point is to find a sound that exists inside the blob, in order to produce S clearly and naturally.

It is never too late to change a speech pattern. Sometimes a surprisingly small adjustment in tongue position or airflow can make a big difference.