Expert: Harriet B Jacobster, Au.D. - 6/4/2009

Question
My son is 28 months old and has been working with a speech therapist for
about a year.  He is starting to get a large vocabulary, but most of his words
sound very similar and he is nearly impossible to understand.  The speech
therapist is concerned because even though he seems to know words he is
having trouble developing sounds, so thank you sounds more like 2 grunts
"unk u" We have had his hearing tested and they tell us he can hear but that
he might have some type of distortion.  I have never heard of this and don't
know what to do?? Please help.

Answer
Hi Heather,
First of all, who gave your son his hearing test and what type of tests were done?  Was it an audiologist who specializes in or does a lot of pediatric testing?  If not, that is the first thing that needs to be done.  A pediatric audiologist knows exactly which tests need to be done for a thorough evaluation and diagnosis.  I'm also not sure what "they" mean by "some type of distortion," but I have a hunch "they" are referring to something known as auditory neuropathy/auditory dys-synchrony.  This is a condition where the auditory nerve doesn't quite deliver the nerve impulses from the inner ear to the brain.  

At 28 months, it's very hard to get exact behavioral responses and to know what the child is really hearing. It is even harder if the child has a speech & language delay/disorder.  In your son's case, I would recommend the following tests: Tympanometry, Soundfield audiometry, Otoacoustic emissions and Auditory Brainstem response audiometry.  The last two tests are especially important in ruling out auditory neuropathy.

In any case, you need to find a pediatric specialist who will work with you, answer your questions, and give you the appropriate recommendations.

Hope this helps.
Harriet B. Jacobster, AuD
Board Certified in Audiology