By Dr. JJ
As I mentioned in our previous post, Getting Straight Answers About Auditory Processing, the topic of auditory processing disorder has historically been controversial. The result is varied practice patterns and children being underserved. Many in the field hold on to beliefs that children under the age of 7 years cannot be tested or treated for auditory processing disorder. While we here at Little Heroes Pediatric Hearing Clinic do not adhere to those same beliefs, they are not totally without *some* foundation. In this blog, we will talk about auditory development and discuss how we can be on the lookout for auditory delays in small children.
Auditory Development
Auditory development is a complex neurological process that starts when babies are still little embryos. Unlike other sensory processing mechanisms in the human body, auditory processing development is prolonged over several years after birth. This is why many believe that auditory processing shouldn’t be addressed until a child is 7 years old. Because, in all truth, some auditory processing skills are still coming together.
Some . . . but not all.
For a long time, pediatric audiologists have understood a generalized timeline for different listening behaviors. These have been a guide for how we assess hearing sensitivity in children. For example, we know that once a baby is around 6 months old, they will begin to demonstrate the ability to pause and look for sounds they hear around them. Later, as children move out of toddlerhood, they should be able to pause, wait, and listen, and let us know when they hear certain sounds. By the time children are 4 years of age, they should be able to listen to and repeat back words or point to pictures that reflect the words they hear. (For more information on how we test hearing in children, check out our YouTube videos!)
In other words, we know that auditory milestones exist. So, even though auditory processing abilities are still developing, certain listening behaviors can be expected for different age groups. And, just like any other developmental ability, there can be delays.
Auditory Milestones
A favorite model to which I refer often with parents is called the Erber Model for Auditory Skills Development. In this model, there are four general listening skills (Detection, Discrimination, Identification, and Comprehension) that are developed sequentially, which umbrella a large variety of listening behaviors. Let’s break this down a little bit.
Detection
This first milestone is detection, and it’s fairly straightforward: Can a child detect when a sound is present versus absent? When you are having your child’s hearing sensitivity tested, this is essentially what we are looking at. How loud do we need to make the sound before your child lets us know that they can detect the sound? This is how we determine whether elevated (louder) thresholds for hearing are mild, moderate, severe, or profound.
So, what does detection look like outside of the sound booth? In the home, a way you can think about detection is whether a child can recognize when their name is being called. Can they recognize you are speaking to them at all? When a child is doing something naughty and you say “no”, do they pause their activities and look at you? Even if they don’t actually follow your instruction to stop whatever they are doing (that skill comes later), it’s important to determine whether your child is demonstrating a recognition that you’re talking to them in the first place.
If you’re child does not respond to you, does that mean they have hearing loss? No. But, of course, that’s why testing your child’s hearing sensitivity will be part of looking at their auditory processing skills, just to be sure. If they have typical hearing sensitivity (meaning, they can hear soft sounds), then this is where listening therapy will play an important role. We can help your child recognize when you are talking to them and teaching them age-appropriate skills for how to respond in those communicative exchanges.
Discrimination
The next step in auditory development is discrimination. Discrimination in the ability to tell that sounds are different from each other. Through my own experiences, I’ve come to categorize these as global discrimination, familiar voice discrimination, voice pattern discrimination, and phonemic discrimination.
Global discrimination: This is simply where I want to make sure that a child can hear that a dog bark is different from, say, the sound of a doorbell. Sounds that, to me, are totally different and should be easily distinguishable from each other. But some sounds can be more similar. For example, the sound of a doorbell from the sound of a dinging microwave. When someone rings the doorbell, will the child pause (detection) and look to the door? Or will they look at the kitchen, the phone, or anywhere else that would be irrelevant to the sound they heard?
Familiar voice discrimination: Here, I am looking at a child’s ability to tell that familiar voices are different from each other. For example, can a child hear that the voices of their parents are different from each other? But, even more than that, if grandma calls on Facetime, will a child recognize that voice as not being a voice in the room, but a voice through the iPad or phone? And can they tell it’s Grandma?
Voice pattern discrimination: This is a fun one to work with. Some children do not recognize changes in voice patterns. This is particularly common in children with Autism. Voice patterns can be a shouting voice, a whispering voice, a singing voice, a regular-speaking voice, a fast-speaking voice, or a slow-speaking voice.
Phonemic discrimination: This is your child’s ability to tell that the sounds (phonemes) of spoken language are different from each other. In my experience, when children have trouble discriminating the sounds of speech, they show many of the classic symptoms for auditory processing deficits. These include delayed responses in communicative exchanges, listening fatigue, and requesting for repetition frequently. Essentially, children can hear what you are saying, but may be processing or decoding what you say as different, even nonsense, words. For example, if you say ‘go get your shoes’, your child could be hearing similar, but different sounds resulting in the phrase ‘do dep your chews’. And it’s not like they’re thinking that they heard that, but they require multiple repetitions and some visual context to understand what it is you said.
Identification
Identification and discrimination are somewhat blended in listening therapy because we check for discrimination by asking the child to identify and label what they hear. However, they are still sequentially developed. As a child is exposed to language, they learn to associate sounds with items, animals, and even people. For example, some of our questionnaires ask if your child hears running bathwater, do they recognize the sound and go to the bathroom? If they hear a siren sound, will they look out the window for a police car (or fire truck, or ambulance)?
Comprehension
This final piece of auditory development is taking all of this listening and making meaningful use of it. This is ultimately the crux of auditory processing, which is (as Dr. Jack Katz says) what you do with what you hear. Thus, if there are breakdowns in any part of auditory development, then likely a child will not proficiently make meaning with what you are saying.
One Example
A good example of this a 6-year-old patient I have. For privacy, we’ll call him Bill. Bill is multiply involved with significant language delays and sensory processing disorder. One of the listening behaviors Bill exhibits is answering questions with irrelevance. We call him our ‘yes man’. You might say ‘what are you up to, Bill?’ and he will likely say ‘yes’. Over the past year or so, Bill has been working with his speech pathologist to understand how to interpret and use/respond to question words, such as who, what, when, where, and why. When thinking of auditory development, a big question in my mind has been: what if Bill can’t discriminate and identify the difference in how these fairly similar words sound? So, during listening therapy, Bill and I have been working on listening to these words and thinking about how they sound different from each other. Together, we talked about how these question words have different sound endings, even if they start the same. So, while listening to these words, Bill learned how to correctly identify which question word was being used by focusing on listening to the ending sound. It was good to note that, initially, Bill was very random in his ability to identify which question word was being used, because he was guessing. But after only a couple sessions of listening therapy, Bill was able to increase his accuracy at identifying which question word was being used to 100%, which has remained consistent. Now that we have achieved both discrimination and identification, Bill may more successfully work with his speech pathologist to start using these question words correctly in communication exchanges and answering questions with higher relevance.
A Final Example
Another kiddo I’ve been working with is 3 years old and has Autism. The biggest concern parents have had is that this kiddo (we’ll call him Everett) acts like he doesn’t hear anything; he never responds to his name being called. It was hard to test Everett’s hearing sensitivity, since these skills of showing sound awareness are required for standard booth testing. However, we had a test from when Everett was an infant showing typical hearing acuity and a newer, objective, hearing screen left us fairly confident that Everett did not have hearing loss. So, we started listening therapy. Our goal: Everett will show awareness to his name being called with 100% accuracy on the first attempt. This took a little bit, but we printed a picture of Everett, and while he did some free play, we would call out Everett’s name. Initially, it took a lot of hand-over-hand work to touch Everett as we called his name, have him touch his picture, and ring a bell. Through this type of conditioning approach, Everett started to look up when his name was called on the second and third attempt. Eventually, Everett would pause his play and look up when his name was called on the first attempt, and he would independently come to touch his picture and ring the bell to let us know he heard his name called. Because he made such progress, we were able to go into the sound booth and get Everett’s first reliable behavioral hearing test showing hearing was, indeed, within normal limits.
Conclusions
While we agree that many complex listening skills are in developmental stages even at older ages, at Little Heroes we firmly believe that some auditory skills should be evident at early intervention ages. And, if they are not, early intervention should be provided to optimize children’s success with listening and auditory processing as they age. If you have questions about what you read here today, contact us! Dr. JJ is obsessed with early intervention and wants to help.
Hope to talk soon!