Speech disorders

A speech disorder, sometimes called a speech impairment or speech impediment, is a condition that makes it hard to form the sounds of speech so that other people can understand you. Some people are born with a condition that affects their speech, and others develop one later after an injury or illness.

What are the symptoms of a speech disorder?

Symptoms vary widely depending on what's causing the problem and how severe it is. It's also possible to have more than one speech disorder at the same time, each with its own symptoms.

Common signs include:

• repeating or drawing out sounds
• rearranging the syllables in a word
• speaking very quietly
• missing sounds off words, for example saying 'bow' instead of boat, or 'ig' instead of pig
• swapping one sound for another, such as 'tar' for car, 'dun' for sun or 'bee' for pea
• having only a small range of sounds available, so one favourite sound gets used in place of many others

In children, some of these are a normal part of learning to talk. By the age of five or six, most children are easy to understand and can say nearly all speech sounds clearly.

Frustration is often part of the picture too. Children can find it upsetting when people around them can't work out what they're trying to say.

Left untreated, speech difficulties in childhood can make learning to read and write harder. Research also suggests children with speech impairments may be more likely to develop anxiety or depression.

What causes speech disorders and who is at risk?

The cause isn't always known. In adults, speech disorders often follow damage to the brain or to the nerves and muscles used for speaking. In children, they're more often part of how speech has developed.

A child is more likely to have speech difficulties if they have:

• a family history of speech, language, communication or literacy difficulties
• a delay or difficulty with listening, attention or language skills
• hearing difficulties, including glue ear
• a physical condition affecting the roof of the mouth or the palate, such as a cleft palate or cleft lip
• difficulty planning and coordinating the movements of the lips, tongue and jaw

For adults, a condition or injury that affects your voice or your ability to speak can bring on a speech disorder at any point in life.

Are there different types of speech disorder?

Yes. Speech disorders can be split into:

• fluency disorders, which affect the flow and rhythm of speech, such as stuttering
• speech sound disorders, which affect how sounds are formed
• voice disorders, which affect the sound of the voice itself
• orofacial myofunctional disorders, which relate to the muscles of the face and mouth.

However, two conditions are more complex.

Apraxia of speech, sometimes called verbal apraxia, follows brain damage that affects the fine control needed to form speech sounds. You know exactly which words you want to say, but the movements needed to say them don't come out right.

Dysarthria happens when brain damage weakens the muscles in the face, lips, tongue, throat or chest. That weakness makes speaking difficult.

Speech sound disorders in children

Around 12 in every 100 children will have a speech sound disorder. Just over half of children with speech difficulties have what's called a phonological delay or disorder, where they can make a sound on its own but can't use it correctly inside a word.

Childhood apraxia of speech is far more rare, affecting roughly one in every 1,000 children.

A speech and language therapist may use several different terms for these difficulties, including phonological difficulties, phonological disorder, speech sound disorder, apraxia of speech or dyspraxia.

How is a speech disorder diagnosed?

A speech and language therapist is the professional who diagnoses speech disorders and advises on what support will help.

As part of the assessment, you or your child may be referred to another service. A hearing test through audiology is common, because hearing difficulties and speech difficulties often go together.

Not every referral leads to a diagnosis. If a child's speech is typical for their age and there's no sign of a disorder, they're likely to be discharged without further treatment.

How is a speech disorder treated?

Speech and language therapy is the main treatment. What it involves depends on the type of speech disorder and, for adults, on the underlying condition causing it.

If you're supporting a child with speech difficulties, the practical advice from speech and language services is:

• speak slowly and clearly yourself, and make sure your child is looking at you when you talk
• model the correct version back rather than asking them to say it properly. If your child says 'dar', reply with something like 'yes, it's a car'
• praise their attempts, and respond to what they've said rather than how they said it
• give them plenty of chances to talk without pressure
• don't pretend you've understood when you haven't. Ask them to repeat it, and if you still can't work it out, say so and ask them to show you

Therapy for children usually works best when the same approaches are used at home and at nursery or school, so the advice is put into practice regularly rather than only in appointments.