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{500}+T{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.