Wednesday, November 8, 2017

Diagnostic Hearing Evaluations and Speech-Language Assessments

Dr. Eve Leinonen, Audiologist
This post was written in collaboration with a colleague who provides exceptional care for clients ages four and older in Naperville, Illinois.   Dr. Eve Leinonen has been practicing Audiology since 2007, when she earned her Doctorate in Audiology from Wayne State University in Detroit, MI.  She has worked in a variety of office settings, as well as with a hearing aid manufacturer as an Outreach Audiologist.  She has been the owner and principle Audiologist of Affordable Hearing Solutions since 2015.  Diagnosed with hearing loss at age 17, Dr. Leinonen can relate on a more personal level to the struggles and frustration that many with hearing loss face on a daily basis.  She is committed to helping patients choose the best treatment option for their hearing loss and lifestyle, and helping them continue to thrive in their every day.

Together, we hope to answer the following:
  • My child can hear me whisper, so why does (s)he need a diagnostic hearing evaluation? 
  • How does fluid and negative pressure in the ears impact hearing?
  • What are the types of hearing losses? 
  • How is a hearing screening different than a diagnostic hearing evaluation?
  • What are the different types of diagnostic hearing tests?
My child can hear me whisper, so why does (s)he need a diagnostic hearing evaluation? 
One of the essential components to a dynamic speech and language assessment is a diagnostic hearing evaluation.  If they haven't already, I strongly encourage families seeking my private speech and language services to schedule a diagnostic hearing evaluation before I assess articulation, expressive, and receptive language skills.  It is critical to rule out a medical factor for a speech and/or language delay that could negatively influence assessments and speech-language therapy.  The American Speech-Language Hearing Association (ASHA) acknowledges that, "Hearing is critical to speech and language development, communication, and learning" in an audiological information series from 2015 titled: The Effect of Hearing Loss on Development.  Specifically, a hearing loss can impact vocabulary development, sentence structure, articulation, and academic performance.  Our sounds are produced at many, different frequencies.  The inability to hear a sound frequency would impact a child's accuracy in producing that sound target.  This is especially evident with quieter sounds:  s, sh, f, t, and k.  A child with a hearing loss may also have difficulty hearing words with -s or -ed endings, making it difficult to both comprehend and express these structures.  If we do not have all the information that we need in planning speech and language services, then we may see limited progress and continued communication delays.

A common misconception is that intact comprehension negates a probable hearing loss.  While this may be true, the only way to be certain that a child does not have difficulty hearing is to complete diagnostic hearing testing.  It is very possible that a child with a temporary hearing loss can continue to follow routine, familiar directions; respond to subtle gestural cues such as eye gaze; and seemingly attend to conversational tasks.  However, it would be challenging for this same child to imitate a variety of speech sounds, especially if they are hearing sounds as though they are swimming underwater.

There are some telltale signs and/or symptoms that indicate a need for a diagnostic hearing evaluation.  Here is a list of the ones that I am most concerned about as a Speech Pathologist:

  • Delay in speech and/or language skills in comparison to siblings/peers
  • History of re-occurring ear infections or sinus infections
  • Difficulty imitating speech sounds 
  • Trouble following directions
  • Excessively loud talkers

How does fluid and negative pressure in the ears impact hearing?
Understanding the effect of fluid on hearing is crucial, especially for young children.  Fluid can give the appearance of normal air conduction levels at times, but the child is losing important speech sounds and cues.  Though it appears normal on paper, to them it sounds as though they are hearing underwater.  Speech and environmental sounds are muffled, thus effecting a child’s ability to hear and understand sounds correctly.  It’s possible that their “normal” levels of hearing without fluid are even better than what is appearing with fluid.  This reduction of hearing can appear to the listener as a “hearing loss” despite showing normal response levels.  Diagnostic testing is important as it will show whether the normal hearing thresholds reveal a conductive component (related to Conductive Hearing Loss and is a gap between air and bone conduction thresholds), thus indicating middle ear concerns.  A child may show normal hearing thresholds, however they could be greatly elevated due to fluid despite still falling in the “normal hearing range”.

Infants and toddlers are prone to excessive fluid build up in the ear canals because the Eustachian tube is parallel, giving fluids a cozy place to stay.  As toddlers grow, the  Eustachian tube begins to slant, which supports natural fluid drainage from the ears.  This is just one of the reasons why we encourage toddlers to sit upright while drinking to avoid adding more fluids into that ear canal. Children can fluctuate in and out of temporary hearing loss conditions and even have this fluid in the ears without an infection.  There are several misconceptions regarding children and hearing loss.  One is that if your child has “normal responses”, then their hearing is fine.  One particular aspect to look at is Tympanometry, which analyzes middle ear function.  Tympanometry can tell us if there is fluid or negative pressure in the middle ear, which can greatly impact hearing. 
What are the types of hearing losses? 
There are three kinds of hearing loss: conductive, sensoirneural, and mixed.  A conductive loss is often a temporary condition brought on by: fluid accumulation, ear infections, or a blockage of the Eustachian tube caused by an allergy.  A sensorineural hearing loss can be the result of a viral infection such as measles, meningitis, or mumps.  This damage to the middle ear may also be caused by head trauma or exposure to extremely loud noise.  Some people are born with a sensorineural loss while others may acquire one in old age.  These videos help explain causation for these losses and common interventions.

Conductive Hearing Loss

Sensorineural Hearing Loss

Mixed Hearing Loss

How is a hearing screening different than a diagnostic hearing evaluation?
It’s important to understand the difference between a hearing screening, and a diagnostic hearing evaluation.  Screenings are typically performed in schools to survey whether a child may have a hearing loss.  This only looks at how the child hears via air conduction (how we hear with sound traveling through the ear canal to the middle ear, inner ear, and then the brain). 

Diagnostic hearing evaluations look at all aspects of the hearing mechanism.  It looks at how we hear via air conduction, bone conduction (how the auditory nerve itself is responding), Word Recognition Scores (Speech Audiometry), Tympanometry and/or Otoacoustic Emissions (OAE). 

What are the different types of diagnostic hearing tests?
There are also different types of diagnostic testing available depending on the child’s age and ability to task during testing.  Visual Reinforcement Audiometry (VRA) is used for children who are old enough (typically 6 months-3 years), or are developmentally delayed, to respond to sounds in their environment, and looks for localization.  This is typically done in a sound booth with external speakers and toys that light up for positive reinforcement when a sound is presented.  Tympanometry and OAEs are typically utilized to make sure there is not any fluid, and that the hair cells in the inner ear are responding to sound stimulation.

Play Audiometry is utilized for children who are old enough (4 years or older) to task to a game or toys, but may not quite be old enough to raise their hand for each beep.  Usually the game involves dropping toys into a bucket when they hear a beep to help the audiologist establish thresholds.  Tympanometry and OAE’s can be performed as well as speech recognition testing.
Older children may be asked to raise their hand or push a button when they hear pure tone “beeps”, repeat words for word recognition score testing, and also Tympanometry and OAEs (if necessary).

If you have any further questions about the impact of hearing on speech and language development, then please visit these links for more details:

Newborn Hearing Screening

Beyond Early Childhood

Childhood Hearing Screening

How We Hear 

1 comment:

  1. Very informative article. Looking forward to more posts in near future.