Given normal pure‑tone audiogram thresholds and bilateral loudness‑discomfort levels of 60–90 dB HL, what is the diagnosis and recommended treatment?

Hyperacusis: Diagnosis and Treatment

The clinical presentation of normal pure-tone thresholds with bilateral loudness discomfort levels (LDLs) at 60–90 dB HL confirms hyperacusis, a condition characterized by abnormally decreased tolerance to everyday sounds that are not uncomfortable to most people.

Diagnosis

The diagnosis is established through the audiometric findings you've described:

• Normal pure-tone audiometry (thresholds ≤20 dB HL across standard frequencies)
• Markedly reduced uncomfortable loudness levels (ULLs/LDLs at 60–90 dB HL, compared to normal values typically >95–100 dB HL)

This pattern is pathognomonic for hyperacusis 1. The bilateral presentation with ULLs "mostly less than 90 dB HL" is the defining audiometric characteristic 1.

Essential Diagnostic Workup

Beyond confirming the audiometric pattern, you must systematically evaluate for:

1. Associated conditions (very common):

• Tinnitus (present in 86% of hyperacusis patients) 1
• Headaches (frequently reported) 1
• Psychiatric comorbidities including anxiety, depression, and stress 2

2. Underlying etiologies to identify:

• Recent acoustic trauma or loud sound exposure
• Head trauma
• Ototoxic medication exposure
• Viral illness
• History suggesting syndromic causes 3

3. Physical examination focusing on:

• Dysmorphic features
• Neurological abnormalities
• Pigmentary or skeletal anomalies
• Signs suggesting syndromic hearing disorders 3

4. Additional audiometric testing:

• Extended high-frequency audiometry (8–16 kHz) - may reveal subclinical threshold elevations 4, 2
• Speech-in-noise testing - to assess functional hearing difficulties 5
• Distortion product otoacoustic emissions (DPOAEs) - typically present/normal in isolated hyperacusis 5

5. Consider temporal bone imaging (CT or MRI) if:

• Diagnosis remains unclear
• Progressive symptoms
• Asymmetric findings
• Other neurological concerns 3

Important Clinical Pitfall

Do not use standard audiometric testing protocols - the British Society of Audiology's recommended starting levels (60 dB HL for ULL testing, standard bracketing for pure-tone audiometry) will exceed the patient's tolerance and cause discomfort in approximately 21–24% of hyperacusis patients 6. Start at lower presentation levels (40–50 dB HL) and increase cautiously.

Treatment Approach

Primary Management Strategy

Sound desensitization therapy is the cornerstone of treatment:

1. Gradual sound exposure therapy

   • Systematic, controlled exposure to progressively louder sounds
   • Avoid sound deprivation (no overuse of hearing protection in safe environments)
   • Use of low-level background sound enrichment

2. Counseling and education

   • Explain the neurophysiological basis (likely increased central gain rather than cochlear pathology) 7
   • Address catastrophic thinking about sound exposure
   • Set realistic expectations for gradual improvement

3. Multidisciplinary referral when available 3:

   • Audiologist experienced in hyperacusis management
   • Otolaryngologist for medical evaluation
   • Mental health professional if psychiatric symptoms present (independently associated with distress) 2

Address Psychiatric Comorbidities

Psychiatric symptoms are independently associated with tinnitus/hyperacusis distress 2. Screen for and treat:

• Anxiety disorders
• Depression
• Stress-related conditions

These require concurrent management as they significantly impact quality of life independent of the audiometric findings.

What NOT to Do

• Avoid recommending constant hearing protection - this worsens hyperacusis by promoting further central gain
• Do not dismiss as psychological - there are measurable physiological changes (decreased ULLs, possible increased central gain) 7, 1
• Do not assume cochlear synaptopathy - evidence suggests this is NOT the primary mechanism in most cases with normal audiograms 7

Monitoring and Follow-up

• Serial ULL measurements to track improvement
• Reassess psychiatric symptoms and functional impact
• Consider genetic evaluation if syndromic features emerge over time (follow-up every 3 years recommended for unexplained cases) 3

Prognosis Considerations

The relatively young age of typical hyperacusis patients (approximately 10 years younger than typical tinnitus/noise-induced hearing loss populations) 1 and the absence of significant cochlear damage suggest potential for improvement with appropriate sound therapy and time, though recovery is gradual and requires patient commitment to treatment.