So as a community speech therapist children with nasality disorders pop up from time to time. Right now I have three on my caseload which is rather more than usual!
Here's a quick anatomy lesson. We have an oral cavity and a nasal cavity. When we make a speech sound the air comes up from our lungs and we can direct it through either one of these cavities. How do we do this? A clever little muscle called the soft palate (or velum if you want the fancy name) which moves up and down to block off or open the nasal cavity. Pretty good huh?
Most speech sounds are made with air being directed out of the mouth. Some are made with air coming through the nose such as 'm' and 'n'. In therapy I sometimes use a little mirror under the nostrils to show the air flow visually.
Hypernasality results when there is too much air coming into the nasal cavity. This can be due to either:
Physical issues, or
Mislearning
So what does this look like? Why does it happen? What can we do?
Physical issues
Sometimes during development in the womb the palate can be formed incorrectly. This might result in a weakness of the soft palate muscles or even a submucosal cleft in the soft palate (see below for a pic).
In my many years of practice I have come across this just once! Although I have referred several more for investigation at my local Cleft Team. These teams consist of highly specialist professionals who can formally diagnose and plan treatment for these kind of difficulties. Treatment might include speech therapy and/or surgery.
Mislearning
When learning to talk toddlers naturally learn to use their soft palate correctly - and to stop food and drink coming through their nose when they are eating! If the soft palate is intact and works properly but there is still hypernasality it is probable that the child has mislearned the sound/s. There are other types of speech sound mislearning too - such as lisps.
There is no particular reason this happens - it's just one of those brain things. The good news is that because our brains are so fabulous we can rewire them with practice! Of course this is much easier for children than for adults as it is harder to change ingrained patterns.
Speech therapy
Speech therapy will focus on:
listening to the difference between oral and nasal sounds and correctly differentiating between them
understanding the mechanism by which we direct the air flow
attempting to make purposeful oral and nasal sounds
practising using an oral airflow for their target sound (commonly 's')
Speech therapists use all kinds of tricks to help with this such as mirrors, Cued Articulation and visuals like the ones below: Mr Mouthy and Mr Nosey!
Once a child can make their target sound orally it usually takes some practice before it generalises into their everyday speech.