Specialist article: speech
LispingWhen tongue function is behind it
Does the S sound unclear, does the tongue slip between the teeth? Here you will learn how a clean S is produced, why lisping often reveals more about the tongue, swallowing and breathing than about speech alone, what studies show and how training can support speech therapy.
Does this sound familiar?
The S does not sound clean, and practising alone does little?
What applies to you or your child?
Tap whatever applies to you.
If several points apply, it is worth looking beyond the individual sound. The S is the finest task the tongue has in speech. In our view, how well it succeeds also depends on where the tongue rests, how you swallow and how you breathe.
How an S is producedWhat the Hamburg study showsThe key points at a glance
- Lisping, technically sigmatism, is the most common articulation disorder in childhood. Up to around the fifth birthday, an unclear S is part of normal development in many children.
- For a clean S, the tongue has to form a fine groove and seal at the sides. If it lies low or forward at rest and pushes against the teeth when swallowing, in our view it often lacks the starting position for this.
- In our view, the function comes first. Training the basic functions of breathing, swallowing and head balance creates the prerequisite for the sound holding up in everyday life, and targeted articulation practice follows where the S does not sort itself out. The Hamburg study also comes to this conclusion.
Video
Lisping: there is more to it than a speech defect
Das Video lädt erst nach dem Klick. Dann werden Daten an YouTube (Google) übertragen.
The term
Lisping: what it means
Everyone knows the word lisping, and yet there is more behind it than a single sound. Specialists distinguish several forms, depending on where the tongue is positioned for the S.
With a lisp, the sibilants are not produced cleanly. It mainly affects S and Z, often also Sh, Ch and the combination Ts. The technical term is sigmatism, after sigma, the Greek letter for S. Some people are hardly bothered by it, while others experience it as a real hurdle at school, at work or on the phone.
old: the age by which 90 % of children in the USA produced the S correctly, analysed across 15 studies with 18,907 children1
of boys and 20.4 % of girls aged between 4 and 6 lisped in a study of 550 nursery-school children in Skopje. Sigmatism was the most common articulation disorder there2
An unclear S at nursery-school age is not in itself a cause for concern. If it persists beyond the age of five, returns after a longer period or is accompanied by an open mouth, mouth breathing or tongue thrusting, it is worth looking at tongue function.
Phonetics
How a clean S is produced: precision work by the tongue
Hardly any sound demands as much precision from the tongue as the S. A difference of just a few millimetres decides whether it sounds sharp or lisped.
For the S, the tongue rises forwards and upwards. Its tip approaches the alveolar ridge behind the upper incisors without closing it completely. The side edges rest against the upper molars and form a seal. In the middle, a narrow groove remains, through which a fine stream of air hits the edges of the incisors. Only there is the bright hissing sound produced.
You can see this groove when the tongue shows its shape. The middle drops and the edges rise. For this to happen in fractions of a second when speaking, many muscles of the tongue have to work together precisely.
If the seal at the sides is missing, the air escapes over the molars. If the tip slips forwards between the teeth, the stream of air no longer hits an edge. Both are clearly audible.
Say “sun” slowly and hold the S. What do you feel?
Tongue and swallowing
More than a speech defect: what lisping reveals about the tongue
The tongue speaks for only a small part of the day. The rest of the time it lies in the oral cavity, keeps contact with the palate and swallows many hundreds to a thousand times a day.
In our view, lisping is therefore usually not just a matter of speech. For the S, the tongue has to go to a place it should know from rest, the front of the palate. If it does not lie there at rest at all, but down on the floor of the mouth or forward against the teeth, every S starts from an unfavourable starting position.
We call this starting position the tongue reference position. The tip of the tongue rests on a small ridge just behind the upper incisors, and the body of the tongue spreads broadly against the palate when swallowing. People often search for the “tongue resting posture”; it means the same thing. We explain this in detail in the article Tongue resting posture and tongue reference position.
The alveolar ridge where the S is produced lies right next to this reference point. In our view, a tongue that constantly finds it at rest and when swallowing has an easier time when speaking.
of 10- to 14-year-olds with tongue-thrust swallowing lisped, compared with none of 21 children in the comparison group without this habit3
of 439 children with mouth breathing showed speech abnormalities, most frequently a tongue between the teeth, followed by articulation disorders and lisping4
Both studies show a co-occurrence, not a cause. But they fit with what we see in practice. In people who breathe with their mouth open, the tongue lies low. In people who press the tongue against the teeth when swallowing, it also seeks support at the front when speaking. You can read more about the swallowing pattern in the article Swallowing and swallowing disorders.
The chain behind it
From an open mouth to a lisped S: the causal chain
In our view, complaints rarely have a single trigger. With lisping, we see a chain in many of those affected that begins long before the first spoken S.
The pattern deviates
Mouth breathing, a dummy used for a long time, thumb sucking or the bottle keep the tongue low and forward. The lips no longer close by themselves.
The body compensates
When swallowing, the tongue braces itself against the teeth instead of the palate. The nervous system stores this compensation as a preferred pattern.
Form follows
Over the years, the palate and the rows of teeth can give way to the pressure. An open bite remains at the front, the upper jaw becomes narrow and the incisors protrude.
The symptom becomes audible
For the S, the tongue finds no edge at the front and no support at the sides. The lisp is often the first thing others notice.
When and how strongly such a chain shows itself depends on the extent of the deviation, its duration and age. Not every child who lisps has an open bite, and an open bite does not necessarily lead to lisping. In our view, however, the common starting point is usually a tongue that has lost its reference on the palate. How the tongue and bite are connected is shown in the case report on open bite.
In our view, the same mouth breathing that keeps the tongue low often accompanies middle ear infections, enlarged pharyngeal tonsils, the adenoids, and misaligned teeth in children. Lisping can be a further, audible link in this chain4. The chain as a whole has not been tested.
The S is the audible part. The function behind it runs all day long.If you only practise the sound, you are working on a few minutes of the day. The tongue, lips and breathing work around the clock, even at night.
Automatic patterns
Why practising in front of the mirror is often not enough
Many people know this. In the practice session the S sounds clean, but in the playground or in conversation it is gone again.
Many children practise conscientiously in speech therapy for years. Under conscious control, the S then works better, but little changes in everyday life as long as the lips hardly make contact and breathing runs through the mouth. We often observe this: a pattern that has run automatically for years can hardly be displaced by insight and short practice sessions alone.
Think of your hand. When you want to scoop up water, you form it into a cup without thinking. Nobody explains to you which finger goes where. The pattern is stored and runs by itself.
The tongue forms its groove for the S in a similar way. If this only works when you think about it, the new pattern is not yet stored. It becomes anchored through frequent, precise repetition in everyday life, and that includes the many swallows and breaths of the day.
Research
Tongue, bite and lisping: what studies show
The connection between tongue function and pronunciation is recognised in the specialist world, but in detail it is less well documented than clinical experience suggests. We say this openly.
In 1985, the Brussels speech researcher Yvan Lebrun evaluated the studies available at the time. Tongue-thrust swallowing was the rule rather than the exception in children under ten. It did not prevent the acquisition of correct sibilants, but it could delay it5. So the swallowing pattern does not seal the fate of the S, but it is not irrelevant either.
on children and adolescents aged between 3 and 18 were included in a systematic review from Ghent and Fort Worth6
What proved robust there was the connection between an anterior open bite and distortions of the front tongue sounds such as S and Z. For a low-lying tongue and biting habits, no clear conclusion could be drawn6
For us, this means: the link between an open bite, the swallowing pattern and lisping is well founded. That a low-lying tongue alone causes lisping has not been proven, because it has hardly been studied.
The absence of a study does not mean that the connection does not exist. It means that it has not been tested.That is exactly why, in this article, we separate what has been measured from what we derive from practice.
Our own study
The Hamburg study: basic functions yes, S sound no
The only randomised study with the FaceFormer also measured lisping. Its result on this point is sobering, and that is precisely what makes it revealing.
At the University Medical Centre Hamburg-Eppendorf, 45 children aged between almost 4 and 17 were randomly assigned to one of two approaches: FaceFormer training at the clinic or myofunctional therapy without a device in speech therapy practices. After six months, 30 children were re-examined. Among other things, a speech therapist assessed how the S was produced7.
of the children in the FaceFormer group habitually breathed through their mouth at the start and after six months, compared with 94.7 and 69.2 % in the comparison group7
of all children examined lisped at the start and after six months. In neither group did the S change significantly7
Mouth breathing, the swallowing pattern and lip strength therefore improved in both groups, faster with the FaceFormer. The S remained largely as it was in both groups. The authors conclude that, once the basic functions of breathing and swallowing have improved, targeted articulation exercises should follow, regardless of the approach.
Context: the groups were small, and there are no long-term data. Sabine Berndsen, co-developer of the FaceFormer, is a co-author. In addition, a Cochrane review found no robust evidence that non-speech oral motor exercises improve pronunciation8. You can find all the studies with our assessment under Studies and science.
Context
Speech therapy and training: two tasks, one goal
In our view, the function comes first and the sound afterwards. Training the basic functions creates the conditions on which speech therapy builds the sound.
Lip closure, nasal breathing, tongue reference position and swallowing pattern are the prerequisite for the sound holding up in everyday life. Targeted articulation practice follows where the S does not then sort itself out. The authors of the Hamburg study also come to this conclusion7.
Speech therapy (logopaedics)
- Introduces the sound and practises it in syllables, words and sentences
- Trains listening, so that the difference between S and a lisped S is perceived
- Transfers the new S into free speech
- Is prescribed by a doctor, usually with cost coverage
FaceFormer training
- Practises lip closure, nasal breathing and the tongue reference position in one sequence
- Trains the swallowing pattern in which the tongue braces itself against the palate instead of the teeth
- Includes head balance, because it helps determine the position of the tongue and lower jaw
- Done three times a day at home, and at night if needed
The two routes are not mutually exclusive. In our view, the training prepares the ground on which speech therapy builds the sound.
The conversation first addresses how the tongue, lips and breathing work in everyday life. Only then does the practice begin. If you train with a practice, it can assess the swallowing pattern and mouth closure and coordinate the training with speech therapy.
But you can also start on your own with the free FaceFormer app and the exercise pages. You can find a practice near you in the practitioner directory.
If speech therapy is already under way, do not stop it. The training can be done alongside it. It is best to discuss with your therapist how to combine the two.
Children
Lisping in children: when you should take a closer look
Not every child who lisps needs treatment. But some signs suggest that there is more behind it than a developmental stage.
Beyond the age of five
The S remains unclear even after the fifth birthday or gets worse again.
Open mouth at rest
When playing, watching TV or sleeping, the mouth is open and breathing is through the mouth.
Tongue forward when swallowing
When drinking or eating, you can see the tip of the tongue between the teeth.
Long-lasting sucking habits
A dummy, thumb or bottle was still in daily use at the age of three or four.
Changes in the bite
The incisors do not meet at the front, or they protrude noticeably.
A pattern that becomes ingrained during growth helps shape the jaw and palate as long as they are growing. In our view, it is therefore worth looking early at tongue reference position, swallowing and nasal breathing in a child who lisps, because the growth window does not stay open.
When the teeth are changing, roughly between the ages of six and eight, many children lisp temporarily because the front incisors are missing. This often resolves once the permanent teeth have come through. Have hearing, the tongue frenulum and the position of the teeth checked by a doctor if the S remains noticeable. You can read more about children and training on the page FaceFormer for children.
Do not correct your child on every S. Instead, casually repeat the word correctly. Pressure makes speaking more strained and distracts from the pattern that really matters.
Training
Training the basic functions: breathing, swallowing, head balance
FaceFormer training does not start with the sound, but with the starting position of the tongue. Breathing, swallowing and head balance are practised in one combined sequence.
In the basic exercise, the FaceFormer sits behind the lips in front of the teeth. The lips enclose it, the tip of the tongue seeks the reference point on the palate, the head balances upright, and breathing is through the nose. This is followed by a swallow with tooth contact.
The negative pressure created in the mouth draws the tongue up to the palate. In this way, it learns its reference through swallowing, not through effort. A mirror helps at the beginning to check the lips and head balance.
The cross-section shows what matters. The FaceFormer sits in the oral vestibule, the lips close, and the tip of the tongue rests at the front of the palate. Exactly where the S will later be produced.
Children aged 2 to 10 train with the FaceFormer ZERO, made of softer material. It is the same size as the ONE; adults switch to the firmer ONE during the day after a few weeks.
- Day 1 to 14
Getting started
Three times a day, 5 basic exercises and 5 pull exercises each time; for children, playfully and with praise.
- Day 15 to 28
Building up
Three times a day, 10 basic and pull exercises each time. Make sure the tip of the tongue stays on the palate when swallowing.
- From week 5
Consolidate
Three times a day, 20 repetitions each time. At night, the ZERO can be added; see night-time use.
- Afterwards or in parallel
Practise the sound
Where the S does not sort itself out, speech therapy establishes the sound and transfers it into words and sentences.
- Over months
The pattern runs by itself
The exercise manual allows six to twelve months until new sequences run without thinking; see Process and duration.
Everyday life
What you can do for your tongue in everyday life
The training works through repetition. A few habits help the new pattern find its place between the exercises too.
Lips closed, nose open
At rest, the lips lie loosely together and breathing is through the nose. That way the tongue stays on the palate almost by itself.
End sucking habits gently
Dummies, thumbs and bottles keep the tongue low and forward. Plan the farewell together and without punishment.
Quick checks throughout the day
Link a quick inner check to something that happens often: where is the tip of the tongue, is the mouth closed?
Head balance during homework and screen time
Set up the desk and chair so that the head balances above the body and does not sink forwards.
Patience instead of pressure
A pattern that has developed over years takes months. Small progress with mouth closure and swallowing is already a step towards the S.
Questions
Frequently asked
Is lisping normal in children?
Up to around the fifth birthday, an unclear S is part of normal speech development in many children. In an analysis of 15 studies, 90 % of children produced the S correctly between the ages of four and five. If the lisp persists for longer, or if an open mouth, mouth breathing or tongue thrusting are also present, it is worth getting it checked.
What is sigmatism?
Sigmatism is the technical term for lisping. Depending on the position of the tongue, a distinction is made between interdental, addental and lateral sigmatism.
What causes lisping?
Often several factors come together. In our view, these usually include a tongue that lies low or forward at rest, a swallowing pattern in which the tongue presses against the teeth, mouth breathing and long-lasting sucking habits. An open bite, gaps between the teeth, hearing problems or a shortened tongue frenulum can also play a role and should be checked by a doctor.
Can the FaceFormer correct a lisp?
The FaceFormer is a training device for the basic functions of breathing, swallowing and head balance, not a speech trainer. In the Hamburg study, mouth breathing and the swallowing pattern improved, while the S did not change significantly in six months. In our view, the function nevertheless comes first, because it is the prerequisite for the sound holding up in everyday life. Where the S does not then sort itself out, targeted articulation practice follows; the authors of the study also come to this conclusion.
Can I do the training alongside speech therapy?
Yes. Training the basic functions can be combined with speech therapy. Do not stop any ongoing therapy. It is best to discuss with your therapist how to combine the two.
Are lisping and braces connected?
There is a documented connection between an anterior open bite and unclear sibilants. Braces can change the position of the teeth, but not the swallowing pattern or the tongue reference position. If the tongue lies further forward against the teeth, in our view the teeth can shift again after treatment. More on this in the article Retainers and relapse.
Can you still get rid of a lisp as an adult?
Movement patterns can be relearned in adulthood too, but it takes patience. In our view, training the basic functions for the tongue, lips and breathing comes first, because they are the prerequisite for a new sound holding up in everyday life. Where the S does not then sort itself out, speech therapy for the sound follows. Expect several months until new sequences run without thinking.
My child has been lisping since their teeth started changing. Do I need to do anything?
If the front incisors are missing, the tongue lacks the edge it needs for the S. Many children then lisp temporarily. This often resolves once the permanent teeth have come through. But if the tongue also pushes forwards when swallowing, or if the mouth is open at rest, it is worth looking at tongue function.
More articles from the knowledge section
Experiences on this topic
Where to go next
Sources
- Crowe K, McLeod S (2020). Children’s English Consonant Acquisition in the United States: A Review. American Journal of Speech-Language Pathology 29(4):2155-2169. PMID 33181047. Source
- Grigorova E, Ristovska G, Jordanova NP (2020). Prevalence of Phonological Articulation Disorders in Preschool Children in the City of Skopje. Prilozi 41(3):31-37. PMID 33500374. Source
- Dixit UB, Shetty RM (2013). Comparison of soft-tissue, dental, and skeletal characteristics in children with and without tongue thrusting habit. Contemporary Clinical Dentistry 4(1):2-6. PMID 23853444. Source
- Hitos SF, Arakaki R, Solé D, Weckx LL (2013). Oral breathing and speech disorders in children. Jornal de Pediatria 89(4):361-365. PMID 23809686. Source
- Lebrun Y (1985). Tongue thrust, tongue tip position at rest, and sigmatism: a review. Journal of Communication Disorders 18(4):305-312. PMID 3894438. Source
- Thijs Z, Bruneel L, De Pauw G, Van Lierde KM (2022). Oral Myofunctional and Articulation Disorders in Children with Malocclusions: A Systematic Review. Folia Phoniatrica et Logopaedica 74(1):1-16. PMID 34107494. Source
- Korbmacher HM, Schwan M, Berndsen S, Bull J, Kahl-Nieke B (2004). Evaluation of a new concept of myofunctional therapy in children. International Journal of Orofacial Myology 30:39-52. PMID 15832861. Hamburg study; co-author Sabine Berndsen is a co-developer of the FaceFormer. Source
- Lee AS, Gibbon FE (2015). Non-speech oral motor treatment for children with developmental speech sound disorders. Cochrane Database of Systematic Reviews 2015(3):CD009383. PMID 25805060. Source
Get started
Ready for the training?
The free FaceFormer app guides you through the basic exercises, counts along and reminds you of your sessions. If you wish, a practice from the practitioner directory can support you.
FaceFormer ZERO + ONE
Both material hardnesses for getting started, day and night. The set for adults.
FaceFormer ZERO
The softer FaceFormer for getting started, for children and for the night.
FaceFormer ZERO Children’s Set
ZERO with hygiene box, plush bag and success book with stamp.
FaceFormer training aims to restore the physiological setting of the basic functions of breathing, swallowing and head balance, with lip closure and the tongue reference position, thereby creating the conditions under which symptoms can improve. It does not replace a medical assessment. You can find practitioners near you in the practitioner directory.
