Pediatric Hearing Loss Identification and Assessment – Key Vocabulary

Learning Objectives

• $7.1$ Identify infant responses to auditory signals & effects of sleep state.
• $7.2$ Components/goals of Early Hearing Detection & Intervention (EHDI).
• $7.3$ Age-appropriate pediatric test approaches & expected child responses.
• $7.4$ Elements of an effective school screening program (equipment, measures).

Key Epidemiological Terms

• Incidence = new cases within a time frame.
• Prevalence = total individuals living with the condition during a period.
• Global childhood HL > $35\,\text{dB}$ in better ear ≈ $34\,000,000$ children.
• $2019$ U.S.: $5,934$ newborns with permanent HL ⟹ prevalence $1.7/1,000$.
• Prevalence rises by adolescence to $3.5$–$23/1,000$.
• Co-occurring disabilities: intellectual $23\%$, cerebral palsy $10\%$, ASD $7\%$, vision impairment $5\%$.

Pediatric Hearing Loss Basics

• Average U.S. prevalence of any HL (≥ one ear) in children/youth: $3.1\%$.
• SNHL = most common congenital sensory impairment; HL = $3^{\text{rd}}$ most prevalent chronic condition.
• Without newborn screening, suspicion often delayed until ≥ $3$ years.

Early Indicators in Infancy (< $3$ mo)

• All infants babble; those with HL gradually reduce vocalizations.
• NH (normal hearing) infants repeat heard sounds, attach meaning, start speaking < $2$ yrs.
• HL infants typically do not achieve comparable speech milestones.
• DIAL tool systematically benchmarks auditory milestones across development stages.

Risk & Screening Tools at Birth

• Apgar at $1$, $5$, $10$ min: Appearance, Pulse, Grimace, Activity, Respiration; low scores ↑ SNHL risk.
• Universal Newborn Hearing Screening (UNHS) mandated/voluntary in all $50$ states + DC.

EHDI Framework

• Screen before hospital discharge.
• Diagnostic eval ≤ $3$ mo.
• Intervention start ≤ $6$ mo.
• Early-identified (<$6$ mo) children show significantly higher speech-language outcomes.

Neonatal Physiological Screening Modalities

Auditory Brainstem Response (ABR)

• Click stimulus; pass/fail.
• Infant must be still/asleep.
• Compare to gestational-age norms.
• Automated ABR: disposable electrodes, minimal interpretation.

Otoacoustic Emissions (OAE)

• Transient-Evoked (TEOAE) click stimulus.
• Detects OHC function; pass/fail; cost-effective.
• Pass ⇒ peripheral hearing ≤ $30\,\text{dB}\,HL$.
• Any conductive component disrupts results; failed OAE ⇒ follow-up ABR.
• Limit: misses retro-cochlear pathologies (e.g., AN/AD) ⟹ combine with ABR.

Comprehensive Pediatric Evaluation

• Goal: discrete ear-specific thresholds for rehabilitation planning.
• Triad: behavioral, electrophysiological, developmental measures.
• Subjective inputs: parental concern, speech delay, child–adult interaction, gait/motor, communication mode.
• Case history critical (see Pediatric Case History Form).

Objective Clinic Tests

• OAE ⇒ confirms hearing no worse than mild loss.
• Diagnostic ABR ⇒ frequency-specific thresholds.
• Immittance ⇒ middle-ear status; Acoustic Reflex ⇒ sensory/neural insight.
• Motionless child essential for accuracy.

Behavioral Test Battery by Age

Birth–$2$ yrs

1. Behavioral Observation Audiometry (BOA)

   • Age $0$–$8$ mo; relies on auditory localization.
   • Two clinicians: one distracts, one presents noisemakers.
   • Failure to localize by $8$ mo suggests HL or cognitive delay.
   • Responses considered Minimum Response Levels (MRLs), not true thresholds.
   • Typical MRLs (dB HL):
     • $0$–$4$ mo: Noisemaker $40$, Warble $70$, Speech $45$
     • Decrease with age to $20$–$25$ dB by $20$–$24$ mo.

2. Sound-Field Techniques

   • Child located centrally with multiple loudspeakers.
   • Responses: searching, activity change, facial change, cry.
   • Soft voice surpasses loud voice effectiveness by $2$ mo; off-effect often stronger.

3. Conditioned Orientation Reflex (COR)

   • ≥ $4$ mo; pairs tone + visual reinforcer; child learns to anticipate.

4. Visual Reinforcement Audiometry (VRA)

   • Corrected age ≥ $6$ mo; headphones, inserts, or field.
   • Change reinforcer to prevent habituation.

$2$–$5$ yrs

• Condition to respond to warble/pure tones via headphones/inserts.
• Work rapidly; frequent praise.

1. Speech Audiometry

   • Initiate session; pictures/objects pointing.
   • Obtain SRT via spondees; if not, measure SDT.
   • Ling Six Sound (/m/, /ʊ/, /a/, /i/, /ʃ/, /s/) gauges frequency-specific audibility when tonal test unreliable.

2. Operant Conditioning Audiometry (OCA)

   • Reward (food/visual) after correct responses.
   • Requires many trials; signals must be aperiodic to avoid patterning.

3. Play Audiometry

   • Demonstrated action (ring-on-peg, block-in-box) per tone perception.
   • Success relies on: motivation, contiguity, frequency/intensity generalization, discrimination, reinforcement.

Electrophysiological Alternatives (any age, esp. difficult-to-test)

• ABR & ASSR; effective during natural sleep or under anesthesia; provide objective thresholds.

School-Age Hearing Screening

• >$5\%$ of public-school students may exhibit HL at any moment.
• Minimal protocol (typically by school nurse):
  1. Grades screened: preschool, K, $1,3,5,7,9$.
  2. Pure-tone $500, 1000, 2000, 4000\,\text{Hz}$ @ $20\,\text{dB}\,HL$.
  3. Tympanometry, speech, OAE if equipment present.
  4. Fail ⇒ rescreen $8$–$10$ wks; second fail ⇒ written parent notice + referral.
• Equipment: portable audiometers, immittance devices.
• Guidelines exist for standardized school screenings.

Functional & Educational Impact by Degree of Loss

Minimal/Mild/Unilateral

• PTA $20$–$40\,\text{dB}$ bilaterally, or HF >$25\,\text{dB}$, or unilateral PTA >$20\,\text{dB}$.
• Up to $35\%$ repeat ≥$1$ grade; $12$–$41\%$ receive special services.
• $2\times$ risk of scoring ≥$2$ SD below norm in math/reading.
• Listening fatigue common; early ID + intervention critical.

$26$–$40\,\text{dB}$ HL

• Miss $25$–$50\%$ of speech signal; >$50\%$ if >40\,\text{dB}.
• Social issues: perceived inattentiveness; fatigue.
• Accommodations: consistent amplification + FM, favorable acoustics, specialist oversight, teacher in-service.

$41$–$55\,\text{dB}$ HL

• Without amplification understand at $3$–$5$ ft.
• Miss ≥$50$–$80\%$ of speech; likely syntactic, vocab, articulation delays.
• Need HA+FM, possible visual language supplement, tailored academic & social support.

$71$–$90\,\text{dB}$ (Severe) & >91\,\text{dB} (Profound)

• Unaided detection limited to loud sounds ≤$1$ ft.
• Optimally aided: may detect speech but miss high-frequency cues; FM needed.
• CI candidacy for >$70$–$90\,\text{dB}$; traditional HA insufficient >$90\,\text{dB}$.
• Communication approach (auditory-oral vs visual) individualized; family involvement critical.
• Intensive early intervention (<$6$ mo) predicts better outcomes; late ID → persistent language gap.
• Classroom needs: captioning, note-taking, visual supports, teacher in-service, peer acceptance facilitation.

Psychosocial & Fatigue Considerations

• HL students often expend greater listening effort → fatigue.
• Risk of negative labels ("daydreaming," "not paying attention").
• Peer relationships may shift toward D/HH community for ease of communication, enhancing identity.

Ethical & Practical Notes

• UNHS ensures equity; delayed diagnosis disadvantages language development & academic success.
• Combining objective (ABR/OAE) with behavioral methods mitigates diagnostic oversights (e.g., AN/AD).
• School programs must balance sensitivity (identify HL) & specificity (avoid over-referral) while considering resource constraints.

Key Formulas & Reference Values in LaTeX

• Pure Tone Average $\text{PTA}=\frac{T<em>{500}+T</em>{1000}+T_{2000}}{3}$
• Screening intensity $I_{screen}=20\,\text{dB}\,HL$ (standard across frequencies listed).
• Prevalence example: $\text{Prev}=\frac{\text{Number with HL}}{\text{Population}}\times1000$ (e.g., $1.7/1000$ newborns).

Connected Resources & Videos (for further study)

• ABR & OAE demonstration (video link supplied in transcript).
• VRA demonstration.
• DPAN friends, "Unfair Spelling Test," "This Is Me" peer perspective videos.
• Services/Accommodations mainstreaming overview.

Summary Tips for Exam Prep

• Memorize EHDI $1$–$3$–$6$ timeline.
• Distinguish BOA, COR, VRA, OCA, Play Audiometry by age & methodology.
• Recall screening frequencies/intensities for school protocols.
• Understand functional impact tiers: minimal, mild, moderate, severe, profound.
• Know objective vs behavioral test advantages & limitations.
• Be able to explain why OAE alone can miss AN/AD.
• Articulate psychosocial ramifications & need for parental involvement, early amplification/intervention.