Pediatric Audiology 101 (Subtitle: Why mild hearing loss can still cause speech problems)

Disclaimer #1: I am not a doctor.  This is my best estimation of pediatric audiology 101.  I had it checked by an audiologist, so that I don't grossly mislead you, but I don't profess to be a hearing expert.

Disclaimer #2: I am also not a real blogger.  I wrote this in Word, and it took me a few days to get it as simple as possible, but I had font issues with copying & pasting it.  Sorry that some parts have abrupt font changes.  I don't know enough html coding to fix it.

Over the past few weeks, I’ve learned a lot about ears, hearing, and data analysis.  Now I’m going to share it all, so saddle up for some scientific good times J

The Ear

First things first, here’s a brief education in Pediatric Audiology.  I present to you: the ear.

As you can see, the ear has three zones---outer, middle, and inner.  Sound waves travel into the outer ear and cause the ear drum to vibrate, which causes the “three ear bones” to vibrate.  Those vibrations then travel through the cohlea (the snail-shaped thing in the inner ear) and the cells in the cochlea send information through the auditory nerve to the brain, which tells you what you are hearing. 

There are 2 families of causes of hearing loss. The first is conductive, meaning that the sound does not get properly "conducted"  from the outer ear all the way to the nerve in the back of the ear system, due to a myriad of issues that could arise anywhere along the pathway.  (This is common in children who might have fluid in the middle ear, ear infections, etc). The second source of hearing loss is sensorineural, meaning the the sound can be conducted through the system properly, but there is a disruption along the neural pathway. 

Since Maya had clean, properly fitted, functioning ear tubes (which were checked immediately prior to the ABR), we are expecting her loss to be sensorineural and *not* conductive.  Additional tests that will be done on July 5 will (hopefully) rule out a conductive component.   (It’s possible that there could be a combination of sensorineural and conductive components, but that will likely leave me with more questions, so I’m hoping that things will be simple.  Ha ha ha.)

So that’s the anatomical side of hearing loss.  Now, let’s look at some data. (Note: the data that I am about to show you is not Maya’s.  It is made up.  Although I share a lot, I don’t feel right about sharing her medical data---that should be her choice.  When I asked her if I could post her data online, she was noncommittal.  So I made up some data and my super audiologist friend created this audiogram based on it, for illustrative purposes).

The Audiogram

I present to you:  an audiogram.

The numbers across the top, from 125 to 8000, represent pitch (or Frequency) of sound, going from low pitches (left)  to very high pitches (right). The numbers along the side, from -10 to 120, represent hearing level in Decibels, going from very soft sounds (at the top) to very loud sounds (towards the bottom).   

The goal of hearing testing is to figure out the softest level  that a child can detect each of the different pitches (so if your data line was right up near the top, you would have great hearing . . . if you were at the bottom, profound hearing loss.)

Here’s the same audiogram with some color coding to make it easier to see the zones.  The green zone is where children with “normal” hearing would show up.  Yellow is “mild hearing loss.”  Red is “moderate hearing loss”.  The lines represent the child’s approximate hearing (X= her left ear, O= her right ear).

So the quietest sound this child can hear would be around 40 decibels, while the quietest sound that children with normal hearing could hear would be anywhere between 20 (for some kids) and -10 (for the supersonic hearing kids) decibels.  You can see on the audiogram that this child has mild hearing loss in the mid-frequencies (1000 Hz) and moderate loss as the frequencies increase (2000-4000Hz).

The other color-coded zone on the audiogram is that blue/grey “speech banana”.  The speech banana is represents the volumes and pitches of average conversational speech (if you want to get more technical, it represents the average conversational pitches and volumes of 2 people with normal hearing talking at about 5-7 feet apart).   

Here, the child’s hearing thresholds are within the speech banana. That suggests that she has access to the sounds necessary to develop spoken language.  A child with this type of hearing loss could still responds well when spoken to, even from another room, like Maya does.   However, this speech may sound much softer to her, and if there is background noise it would become difficult for her to hear and understand conversational speech.

But here’s what’s really interesting.  Maya’s hearing loss follows a loosely similar pattern to this made-up data, in that her hearing loss is slightly more pronounced at high frequencies.  When we heard that her impairment was more significant at higher pitches, we thought “Well, what’s high pitched?  Dog whistles, microwaves beeping?”  What we didn’t know what that every speech sound has its own frequency.   Check out the letters on the audiogram . . . you can see that the j-m-d sounds are low pitched, p-h-g are in the middle, and f-s-th are high pitched. 

The configuration of this child’s hearing loss would suggest that she's getting the high frequency consonants f,s, th, etc. inconsistently, or missing them entirely.  So, even a child with mild hearing loss can have speech issues, because they just can't hear certain letters.  (That might be an overenthusiatic use of bold/underlining, but it was a big lightbulb moment to me.)  The letters in the 1000-2000 range would probably be inconsistent or unclear as well.  And why is there no data below 1000 Hz?  That’s because the background noise in the operating room makes it impossible to test low frequency sounds.  (And this is why more testing is usually necessary after a sedated ABR, to gather data on the lower frequencies and to check on that whole conduction thing I mentioned before).

So, Back to Maya

We’ve always thought that Maya could hear well, because of her responses (“What does an H say?”  “Hhhhhaa”).  However, our apartment doesn’t have a lot of background noise (like school will) and kids with hearing impairment are apparently highly adaptable and skilled at compensating.   The knowledge that she is hearing impaired is certainly making us re-think the times when she “stops paying attention.”  Did she just decide to suddenly ignore us, or is it that she just couldn’t hear/understand the last set of directions? 

 I’m also rethinking some of her oral-motor issues.   If I say, “Maya, say ‘dada’” and she replies “Baba!” is that because she couldn’t get her mouth organized enough to say “dada” or because she misheard me? 

Who knows.  But you can bet your bottom dollar that I’ll be taking some good before-hearing-aids/after-hearing-aids observations and videos for comparison’s sake.

The Take-Home Message

I’ve done a lot of reflecting on the roles of parents, doctors, and various clinicians in diagnosing hearing loss.  Especially in terms of the advocacy, vigilance, and thoroughness that all of the players have to bring to the table.  If I had to sum it all up in one sentence, I would say this:   “If at first you don’t succeed (in getting clear audiological data), try, try again.”

Also applicable, the good old “When you assume (that your child hears normally because she understands and responds to you most of the time) you make an ass out of u and me."

(Well, not me.  Just you.)

Jokes aside, the big picture thing that I’ve learned is that hearing loss can be very tricky, because young kids are highly adaptable and learn to how to work around their weaknesses.  So, if you have a child with speech delays, do your best to get clear audiological data.

Even if you think that your kid can hear. 

Really!

I almost cancelled the ABR when I realized a few days beforehand that I can stand in the kitchen and say “What does a ‘B’ say?” and Maya can respond from the living room “Ba!”.  I thought, surely, if she can hear that I said B (instead of D or P) from a room away, without seeing my lips move, then her hearing must be fine.   But it’s not.

Make sure that you are working with an ENT that you trust, and explore the possibility of hearing impairment.    Every time our ENT said “Oh, has it been 6 months?  Let’s get her in for the behavioral hearing eval again.” I would roll my eyes and dread the appointment---which typically ended with a breakdown (on Maya’s part) and frustration (at spending our time in another appointment that yielded not much information).   But thank goodness we all stuck with it.

Nightswimming*

(Actually, day swimming.  But if I write Nightswimming then the REM song starts in my head and I love having that song playing in my head, so I'm keeping it.)

We've had two days of oppressive heat & humidity here . . . what better day to re-join the pool?  As a suburb girl, I'm a fan of the outdoor summer pool---but here in our neighborhood the indoor one turned out to be cheaper (and it has longer hours, and includes a gym membership----how is that even possible?) . . . regardless,  we'll be hanging out (indoor) poolside this summer.

Before we could leave for the pool I told Maya "We have to take Parker out to go potty" and I went to find my sunglasses . . . when I turned around, she was holding the leash!

Is this what you're looking for, Mom?

Parker!  Stay still!  Don't eat the leash!  We have to get this on so quick . . . mama said she's takin' me to the pool!

Who cares if the leash isn't on?!  Let's go!

Fun times were had by all at the pool.  I took some pictures on my phone to text to Dave (in a sharing-the-cuteness way, not a you're-at-work-and-we're-at-the-pool way):

This was "Maya, make a silly face!"

This was "Maya, smile!"  Maybe we need to work on making a smiling face.

The most amazing part of the pool visit was this sign:

 3 FEET DEEP

We were hanging out by the stairs and Maya was furiously pointing at it and making noises (the girl loves letters).  Just for kicks, I took her over and said Where's the E? and she pointed at one of the E's. 

Where's the D? Got it. 

Where's the P? Right again.

Where' the 3? Pointed at it, and then held up 3 fingers (like we taught her for her birthday).

Holy crap.

She's such a little sponge, just constantly soaking things up.  I haven't been doing any sort of focused letter stuff with her, other than watching Leapfrog Letter Factory once or twice a week and singing the song from it.  I haven't been showing her the letters (and certainly not the numbers).  But I will be now :)

 Daddy, when I'm done swimming I get to wear a pretty dress and pink sandals!!!

I tried to get a picture of her in the dress when we got home, but all I got were a bunch of shots that look like this:

She's too quick :)  (How great is that to say?!)  It's not quite running, but it's some sort of if-you-walk-any-faster-you'll-certainly-land-on-your-face pace, and I love it.  I love the fact that sometimes I have to do a few little joggy steps to get to her :)

And a quick post-hospital update . . .

True to form, Maya's still a little off from the anesthesia/hospital experience.  I feel like biologically it shouldn't last this long, but it seems to always take her a solid 2-3 days before she's totally back---she's taking longer naps, going to bed earlier, and trying to quit her therapy sessions midway through by employing the I-just-need-a-hug tactic on her therapists (with varying degrees of success).

As for me, I've spent the past two days exchanging dozens of emails with a good friend who happens to be a pediatric research audiologist in LA.  I made sure to get a tiny bit of data on Tuesday that I could feed to her, and based on that she created a graph to teach me the basics of hearing threshold data.  When I wondered about the reality of hearing aids, she sent me pictures of the pediatric aids from her center.  When I asked about the process of making Maya's hearing aids, she sent me a detailed play-by-play of how they create the new hearing aids where she works, what to expect at the appointments, and the brand and model number that her coworkers recommend based on Maya's case history.  When I started to struggle and question the validity of the findings (more on this some other time, but considering that we've already had one ABR that I don't trust, how can I be 100% certain of this one?) she consulted with some more people on her end and passed along the consensus of their thoughts.  Since Tuesday we've traded 22 emails, several of which included pdfs that she made to teach me about things. 

And she's another one of my internet friends. 

Another one that I've never met.  

We did have one telephone conversation a few weeks ago---helping me figure out if the sedated ABR was a good next step or more-than-what-was-necessary.  But other than that, she's a message board/Facebook/email friend.  Seriously, I'm so happy to live in this age of internet networking---where I can meet intelligent, wonderful women who have a great impact on my life.  

Thanks, Amy :)

(Re)united and it feels so good . . .*

We had an awesome weekend. 

Our first ever weekend road trip since Maya was born, and Maya's first hotel stay.  On Friday night we drove to my sister's place, where Maya ran (and fell) in the yard with her cousins nonstop for 4 hours straight.   I would have taken pictures, but I don't think it would have been physically possible to get all of the kids in the same frame anyway . . . and I was too busy stuffing myself with lobster rolls and homemade desserts to try :)  The running may have overtired her a bit, as she cried hysterically for most of the remaining drive to the hotel. 

We were a little nervous about her sleeping abilities in hotel room port-a-crib (pack n play), but she was super psyched to see a "special crib":

My own room?!?  And a special crib?!?  This is fantastic!

Saturday morning we went over to an old friend's house for a brunch playdate . . . which sounds normal enough.  Except for the fact that we've never met before.  Or spoken on the phone.  She's a friend that I "met" online---a few years back, and have since traded email, chatted online, etc. 

I'm betting that half of the people reading this are thinking "Cool!  I wish I could meet up with some of my online friends!" and the other half are thinking "Isn't talking to strangers on the internet an activity reserved for homicidal maniacs and pedophiles?"  

But really, I'm lucky enough to have "met" a bunch of amazing online friends (remember those awesome cardboard party animals?  They came from one.  And when we needed extra scrabble tiles to add Parker's name to Dave's scrabble plaque another internet buddy sent some over.).  And besides just mailing me stuff (lol), these are people who celebrate each other's victories and lend a lot of support in times of struggles.  So don't knock "imaginary" friends until you've tested the waters.

Hello, friend.  (See, we don't look that weird.  No homicidial maniacs here.)

And Maya loved playing with some new friends, too.  Every time that we're around other kids I feel some inner part of me holding my breath for Maya.  A little voice that thinks "Will they think it's weird that she doesn't talk to them?  Or that she walks a little bit differently than they do?" But her two (adorable) girls were oh-so-ready to play with Maya . . . they ran, played with chalk, jumped (or bounced, in Maya's case) on a trampoline :) They had even learned some signs to do with her . . . how sweet is that?

Ok, ladies, we've got the chalk.  What's the game plan here?  A landscape scene?  Animals?  Scribbles, perhaps?

After brunch, it was on to my 10 year college reunion.  An afternoon of running on the green and catching up with friends, followed by an evening of dinner, drinks and on-campus fun.  My dad came up to babysit Maya at the hotel so we could have a child-free evening (and Dave's parents babysat Parker for the weekend, so we were dog-free as well).

We returned this morning and I went out to check the pigeon (I had a feeling the hatching would be soon, because some other pigeon was visiting last Thurs & Friday---I had never seen him/her before, and I thought it might be a sign that something was changing).  Sure enough, one of the eggs had hatched---apparently just before we got in---the chick was still wet and wiggly.

Baby pigeon butt sticking out from under mom, with the other (unhatched) egg in the foreground

I left the video camera running for a while, with the hopes of catching footage of the other egg hatching.  No dice, but I did get to see Mama Pigeon (MP) pushing the egg back under her, which was pretty cool:




I think I mentioned before that baby pigeons are seriously the weirdest looking animals ever---bright yellow, gangly, awkward.  You may have nightmares.  You've been warned.

I had to refill Parker's dog food container tonight, which really bugs MP (you may remember that this refilling procedure was what first outed her prescence to us).  Anyway, sure enough, she flew onto the terrace railing while I refilled . . . and of course, I had my camera and video camera ready just in case she decided to leave.  I slipped off my rings and put them next to the baby for a size comparison---it's tiny and so weird looking:

Here it is wiggling:

(Don't worry, MP was back on the nest as soon as I walked away.  She picked an unfortunately high traffic area for her nest, but she seems to have quickly gotten used to Dave and I puttering around.)

We're waiting to see if the other egg hatches too.  I feel like I don't have time to do any cool animal behavior stuff anymore, so the universe has brought me my own little case study, right onto my terrace :)

A fantastic trip from start to finish :)

In other news, Maya's ABR is on Tuesday.  I'm nervous, and I feel bad for her poor little unsuspecting self.  But I'm going to not think too much about it until tomorrow night.