Prognosis for Hearing Loss in Tympanic Membrane Rupture
Most adults with traumatic tympanic membrane perforations experience spontaneous healing with complete or near-complete hearing recovery within 6-8 weeks, particularly for small to moderate perforations. 1, 2
Expected Hearing Loss Pattern
- Conductive hearing loss is the predominant pattern, occurring in approximately 87.7% of traumatic perforations, with the injured ear showing significantly worse hearing thresholds compared to the unaffected ear 2
- The hearing loss is frequency-dependent, with the largest losses (10-30 dB) occurring at low frequencies (250-1000 Hz) and progressively smaller losses at higher frequencies 3, 2
- Most perforations cause only mild conductive hearing loss (typically 15-25 dB air-bone gap), along with aural fullness and mild tinnitus 1
Factors Predicting Hearing Recovery
Perforation Size
- Larger perforations produce greater hearing loss at all frequencies, with air-bone gaps increasing proportionally with perforation size 3, 4
- Small perforations have the best prognosis for spontaneous closure and hearing recovery 1
Middle Ear Volume
- Ears with small middle ear and mastoid volumes (≤4.3 ml) have significantly worse hearing outcomes, with air-bone gaps 10-20 dB larger than ears with larger volumes (>4.3 ml) 3, 4
- This factor is often overlooked but critically impacts prognosis 3
Perforation Location
- Contrary to traditional teaching, perforation location (anterior vs. posterior) does not significantly affect hearing outcomes, with differences of only 1-8 dB at most 3
- However, one study suggested posterior perforations may have slightly larger hearing loss, though this finding is inconsistent 5
Timeline for Hearing Recovery
- Significant hearing improvement occurs within the first 6 weeks post-injury, with notable closure of air-bone gaps during spontaneous healing 2
- Low-frequency hearing recovery is significantly better than high-frequency recovery during the healing process 2
- Most small perforations resolve spontaneously within 1 month; perforations that fail to heal by 1 month require otolaryngologic referral 1
Red Flags Indicating Poor Prognosis
- Conductive hearing loss >30 dB suggests ossicular chain disruption, requiring immediate specialist evaluation 1
- Profound sensorineural hearing loss signifies inner ear nerve damage with permanent hearing loss potential 1
- History of vertigo, nausea, and vomiting at time of injury indicates possible ossicular disruption or inner ear involvement 1
- Chronic ear discharge worsens hearing outcomes—the longer the duration of discharge, the greater the hearing loss 5
Management to Optimize Hearing Recovery
- Keep the ear completely dry using earplugs or petroleum jelly-coated cotton balls when showering, and avoid swimming until healed 6, 7, 8
- Avoid ear irrigation and pneumatic otoscopy, as these can worsen injury or introduce infection 8, 1
- If topical antibiotics are needed, use only fluoroquinolones (ofloxacin or ciprofloxacin-dexamethasone), as aminoglycosides cause permanent sensorineural hearing loss through perforations 7, 8
When to Obtain Formal Audiometry
- Obtain baseline audiometry at least 6 weeks post-injury to document hearing status after initial inflammation has resolved 6
- Earlier testing may underestimate actual hearing recovery potential 6
- Repeat audiometry is indicated if symptoms persist beyond 6-8 weeks or if surgical repair is being considered 6
Surgical Intervention Considerations
- Perforations that fail to heal spontaneously by 90 days require specialist evaluation for possible surgical repair 6
- Delayed treatment increases risk of permanent hearing loss and structural complications including retraction pockets, ossicular erosion, adhesive atelectasis, or cholesteatoma 9, 6
- Tissue-engineered myringoplasty with basic fibroblast growth factor achieves 98.1% closure rates versus 10% with conservative management alone 8