Hearing

Hearing and Children with PKSJames Zeigler Au.D.1Thank You Protocol for screening and evaluating hearing loss in infants and young childrenConductive and sensorineural hearing lossesAmount of hearing lossAudiogram overviewHearing Tests - abr and sound booth tests Hearing Aids

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JCIH 2007www.jcih.org3Early Hearing Detection and Intervention (EHDI): What is it?Hearing loss is the most common disorder screened in the newborn period and one of the most cost effective to treat EHDI is an integrated system that brings multiple disciplines together for the single purpose of detecting and treating hearing loss as early in life as possibleThere must be a seamless integration of universal newborn screening, prompt diagnosis, effective intervention and tracking.4Through the EHDI process, we are trying to bring together everyone involved in helping with hearing loss. A coordinated EHDI program is necessary because:Hearing loss is a frequent condition Early diagnosis and treatment improves outcomesMultiple disciplines and agencies are involved in making EHDI a success

Hearing loss is an important public health concern. Each year in the United States, more than 12,000 babies are born with a hearing loss, making it the most frequently occurring condition identified through newborn screening. Left undetected, hearing loss in infants can negatively impact speech and language acquisition, academic achievement and social and emotional development. Even mild hearing loss can significantly interfere with the reception of spoken language and education performance. If hearing loss is detected early, however, these negative impacts can be diminished and even eliminated through early intervention. EHDI Program GoalsScreen all newborns by 1 month of ageDiagnose hearing loss by 3 months of ageLink the child to intervention by 6 months of age to maximize developmental, educational and communication outcomesProvide support and education for families about the importance of detection and treatment of newborn hearing loss

Remember!! 1 - 3 - 6

5PA EHDI Program Goals which are consistent with national goals.Why the rush??

6Anu Sharma Ph.D. Cortical Auditory Potentials

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8Boys Town National Research Hospital Study of Earlier vs. Later

129 deaf and hard-of-hearing children assessed 2x each year

0.81.21.82.22.83.23.84.24.80123456Identified 6 mos (n = 104)Age (yrs)Language Age (yrs)Moeller, M.P. (1997). Personal communication, moeller@boystown.org9Anatomy and Physiology

10Anatomy and Physiology of HearingDivided into 4 parts

Outer EarMiddle EarInner Ear

Central Auditory Nervous System11Structures of the Outer EarPinnaGathers sound wavesAids in localization

12Structures of the Outer EarExternal Auditory Canal or Ear CanalApprox. 1 inch longS shapedAmplifies sound by 3 to 6 dBIsolates the eardrum from physical damage Cerumen glands moisten/soften skinPresence of some cerumen is normal

13Structures of the Outer EarTympanic Membrane or Ear DrumThin membraneForms boundary between outer and middle earVibrates in response to sound wavesChanges acoustical energy into mechanical energy

14Structures of the Middle EarOssicles Ossicular chain = malleus, incus & stapesFocus/amplify vibration of TM to smaller areaEnables vibration of cochlear fluidsMalleus = HammerAttaches to TMIncus = AnvilConnectorStapes = StirrupSmallest bone in the bodyFootplate inserts in oval window of the cochlea

15Structures of the Middle EarEustachian TubeConnects middle ear cavity to nasopharynxEqualizes air pressure in middle earNormally closed, opens under certain conditionsMay allow a pathway for infectionChildren grow out of most middle ear problems as this tube lengthens and becomes more verticalPKS and high arch palate?

16Structures of the Inner EarCochleaSnail shaped cavity within mastoid bone2 turns3 fluid-filled chambersContains Organ of CortiConverts mechanical energy to neuro-electrical energy

17Structures of the Inner EarOrgan Of CortiEnd organ of hearing3 rows of Outer Hair Cells1 row of Inner Hair CellsTectorial and Basilar MembranesCochlear fluids

(From Augustana College, Virtual Tour of the Ear)18Structures of the Inner EarHair CellsFrequency specificLow pitches = apex of cochleaHigh pitches = base of cochleaFluid movement causes deflection of nerve endingsNerve impulses (electrical energy) are generated and sent to the brain

19Structures of the Central Auditory SystemVIIIth Cranial Nerve or Auditory NerveBundle of nerve fibers (25-30K)Travels from cochlea through internal auditory meatus to skull cavity and brain stemCarry signals from cochlea to primary auditory cortex, with continuous processing along the way

20Structures of the Central Auditory SystemAuditory CortexWernickes Area within Temporal Lobe of the brainSounds interpreted based on experience/association

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Anatomy of Hearing LossSite of ConductiveLossSite of Sensori-neural Loss22Types of Hearing LossConductive = Outer and/or Middle EarSensorineural = Inner EarMixed = Outer and/or Middle Ear and Inner EarAuditory Neuropathy Spectrum Disorder (AKA Auditory Neuropathy / Dys-synchrony) = Central Auditory System

UnilateralBilateral23

Deciphering the AudiogramHorizontal axis: Frequency information (pitch)

24Deciphering the AudiogramVertical axis: Sound energy (loudness)

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Loudness Soft to LoudFrequency Low Pitch to High Pitch

SPEAKERS NOTESThis is an audiogram. Frequency or pitch is shown across the top of the audiogram. CLICK NOW FOR GRAPHIC. The frequencies range from 125 Hertz (Hz) to 8000Hz. You can think of the frequency portion of the audiogram like a piano keyboard. Sounds on the left portion of the audiogram are low pitched, bass quality sounds; with the lowest pitch on the audiogram being 125Hz. As you move to the right, toward 8000Hz, sounds get higher in pitch and have a tenor quality.

Intensity or loudness is shown along left side of the audiogram. CLICK NOW FOR GRAPHIC.The further you move down the audiogram, the louder sound becomes. For example, a 10dB sound is as soft as a whisper, while a 110dB sound is as loud as an airplane.

Familiar sounds are plotted on this audiogram, revealing at what frequency and loudness level these sounds occur. For example, a lawn mower is a very loud, low pitched sound, while the s sound is a very soft, high pitched sound.

The shaded area represents where the sounds of speech take place. If you look closely at this area, you will notice that the sounds of speech occur between approximately 15-50dB from approximately 250 to 8000Hz. Vowels tend to be lower pitched and louder than consonants.

Normal HearingMild LossModerate LossModerate Severe LossSevere LossProfound LossSPEAKERS NOTES. The audiogram is broken down into different parts that reflect the degree of hearing loss a person has. Click Now for GraphicThe normal range of hearing is 0-20dB.Click Now for GraphicA person has a mild loss if their thresholds are from 20-40dB.Click Now for GraphicA person has a moderate loss if their thresholds are from 40-55dB.Click Now for GraphicA person has a Moderate-Severe loss if their thresholds are from 55-70dB.Click Now for GraphicA person has a Severe loss if their thresholds are from 70-90dB.Click Now for GraphicA person has a profound loss if their thresholds are 90dB and greater.

As you can see, a person with a mild loss will be unable to hear sounds in the normal range and person with a moderate loss will be unable to hear sounds in the normal and mild range. This pattern will continue for each successive degree of hearing loss. A person with a profound hearing loss will be unable to hear any of the sounds of speech and most environmental sounds.

Audiogram of Familiar Sounds

28Plotting Results on an Audiogram

White area is inaudibleTan area is audible

From: Glen R. Meier, M.S., CCC-A, FAAA

http://www.audiologyawareness.com/hearinfo_audiogramread.asp

29Conductive Hearing Loss (CHL)Caused by damage, disease, or malformation of the outer or middle earSound is prevented from reaching the inner earSound perceived as muffled or weak 30Conductive Hearing Loss

31Sensorineural Hearing Loss (SNHL)Caused by damage, disease, or malformation of the inner earSensory loss associated with inner ear damage Neural loss if hearing nerve cannot send the impulse to the brainSound perceived as distorted AND weak32Sensorineural Hearing Loss

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Hearing loss and Prosthesis SimulatorHeLPSDemo #1 Severity of sensorineural hearing losshttp://www.sens.com/helps/helps_d01.htm

Demo # 3 Mild Conductive and Mild Sensorineural hearing loss comparisonhttp://www.sens.com/helps/helps_d03.htm - 34Hearing Test CategoriesObjective tests or physiologic testsDo not require child's participation

Subjective testsRequire the child to participate in evaluation35Types of Subjective Auditory TestsSound Booth TestsVisual Reinforcement Audiometry (VRA)Play AudiometryConventional AudiometryHearing for Speech

All subjective tests evaluate HEARING: requires consistent responses from the child

36Types of Objective Auditory Tests Tympanometry- middle ear

Otoacoustic Emissions (OAEs) -inner ear

Auditory Brainstem Response (ABR)-auditory pathways in brainstem

DO NOT evaluate Hearing37TympanometrySpecial earplug placed in the ear canal produces a puff of airThe technique measures the response of the eardrum to the change in air pressureTympanometry evaluates only the middle ear and does not provide information about hearingUsed to determine if (temporary) middle ear abnormality contributes to hearing loss38Otoacoustic Emissions (OAEs)Special earphones placed into the ear that deliver clicking sound within the ear canalCochlea responds by producing a soundProbe detects this cochlear emission, which is recorded on computerOAEs detect presence or absence of hearing loss, but cannot assess degree of hearing impairmentMethod for newborn hearing screening39Auditory Brainstem Response (ABR)Special earphones deliver sound to earElectrodes on the scalp measure brain activity in response to soundResulting waves provide information on the integrity of the neural pathwayABRs can estimate degree of hearing loss at different frequenciesUsed for infants and children who cannot consistently respond to subjective testing40Audiologic EvaluationShould be performed by audiologists experienced in pediatric hearing assessmentInitial audiologic test battery to confirm hearing loss must include: physiologic measures objective testswhen developmentally appropriate, behavioral methodsCompleted in both ears regardless of the results of screening testsJCIH - Changes in 200741Audiologic Evaluation Birth to 6 months (Developmental Age)Child and family historyFrequency-specific AC (air conduction) ABR;Bone conduction, frequency specific ABR, when indicatedClick-evoked ABR if infant has risk indicators for neural HL, any infant demonstrating no response on FS-ABR requires click-evoked ABROAE (DPOAE or TEOAE)Tympanometry using 1000-Hz probe toneObservation of auditory behavior As cross-check; not for assessment or amplification fittingJCIH 200742Audiologic Evaluation 6 months to 36 monthsChild and family historyParent report of auditory and visual behaviors and communication milestonesBehavioral audiometry (VRA, CPA), including:Pure-tone audiometry across the frequency range for each earSpeech detection and speech recognition measures OAE testingTympanometry & Acoustic Reflex Thresholds ABR testing if responses to behavioral audiometry are not reliable, OR if ABR testing has not been performed previouslyJCIH 200743AmplificationInfants diagnosed with permanent hearing loss should be fit with amplification within one month of confirmation of hearing lossJCIH 200744Treatment and intervention for hearing lossMedical interventionsurgical treatment treatment for chronic middle ear disorder

Hearing aidsCochlear implantsFM systems

45Treatment and intervention for hearing lossEarly intervention for overall developmentCommunication modalitiesEmotionalSocialCognitiveWhoEarly interventionistsSpeech-language therapists specialized in hearing impairmentEducators for the hearing impaired

46Monitoring and managing hearing lossHearing can change can get worsePlan for future needs - amplification flexibility Monitor hearing aid/cochlear implant function trouble shootProvide educational input and consultation (classroom modifications, FMs, educational strategies)

47How to work collaboratively with audiologistsOut reach efforts can be individual or group

Mutual information sharing

Keep asking questions

48Take Home MessageInfants can and should be assessed as soon as possible to maximize development of maturing auditory skills; sets the stage for language developmentFamily choices for intervention often includes hearing aids/cochlear implants AND early intervention (communication strategies)Questions about hearing? Ask your Audiologist

49ResourcesYou tube video on hearing: Brandon Pletschhttp://www.youtube.com/watch?v=PeTriGTENoc&NR=1

Hearing screening information for parents:www.babyhearing.org American Speech,Language and Hearing Associationwww.asha.orgAmerican Academy of Audiologywww.audiology.orgPennsylvania Early Hearing Detection and Interventionwww.paearlyhearing.org

50Contact information: jzeigler@liu18.org

Thank You!51