Is there a difference between the MLU of children who have Cochlear Implants (CIs) and children with typical hearing? My gut reaction would be ‘yes’ because MLU is something we intensely target in deaf education. But does research support that this intense focus on MLU is really needed?
The answer is ‘yes.’ Research (unfortunately) reports there is a difference in the MLU between these two groups of children. But the fact that there’s a difference in MLU isn’t the most important thing revealed in the research. The flashing bright lights in the research were why and how of this MLU gap.
Let’s review some background knowledge before we look more into the why’s and how’s.
MLU stands for Mean Length of Utterance. MLU is kinda like the average number of words that a child says each time they talk. Children typically start talking in longer sentences as they get older. When you starting analyzing MLU, you see that the longer MLU has more complex components of language.
Here’s the average MLU at each age
|12-26 months||1.0-2.0||“Milk” “More Milk”|
|27-30 months||2.0-2.5||“Go out”
“Pick me up”
|35-40 months||3.0-3.75||“More milk, please”|
|41-46+ months||3.75-4.0||“I want more milk”|
(Source: Brown, R. (1973). A first language: The early stages. London: George Allen & Unwin.)
With this background knowledge in mind, let’s get into the why’s and how’s!
Two Main Points of the Study
* Children with typical hearing have a higher MLU than children using cochlear implants (Baba & Sherla, 2012). In the study, children with CIs had an MLU of 2.2-3.3 and children with typical hearing demonstrated an MLU of 4.3-5.6.
* There’s a positive correlation between MLU in children with CIs and their total auditory experience (Baba & Sherla, 2012).
Why is MLU Important?
MLU is definitely getting a lot of attention here, but what makes it so important? MLU is important because it’s a result of auditory experience and with a longer MLU comes more complex language skills. (This is the big WHY of the research!)
This goes to show that having a Cochlear Implant or Hearing Aid (HA) isn’t the end-all, be-all solution. CIs and HAs are tools that provide a child access to auditory input. There has to be adequate auditory experience to develop language.
Increase and Improve Auditory Experiences
Use Listening and Spoken Language strategies to intentionally provide effective and a greater variety of auditory experiences. (Here’s the how!)
Listening and Spoken Language strategies can be used literally anytime and anywhere. For posts and tutorials on these strategies, check out Auditory Bombardment, Narration, Acoustic Highlighting, and Auditory Sandwich.
In addition to using these strategies in everyday routines, you also should take steps to improve the listening environment of your home. This can help to reduce auditory fatigue. By making it easier for your child to pick up auditory input, they can have a better auditory experience.
So if you are a parent of a child with CIs, continue working to give your child as much auditory exposure and listening opportunities as possible. Continue to use your Listening and Spoken Language strategies and if you’re not sure what these strategies are, check out this page.
Thank you so much for reading!
Did the results of the MLU study surprise you? Let us know in the comments below!
Babu, L., & Sherla, S. (2012). Mean length of utterance in children with cochlear implant versus normal hearing children. Language In India, 12(12), 402-435.