Otosclerosis

A hereditary disorder causing progressive deafness due to overgrowth of bone in the inner ear.

Practical Audiology

​Signs from the Case History

• Maternal Family Hx/Pregnancy
• Occlusion effect while talking or chewing
• Swartzes Sign; red bulge on medial wall of ME Space

Site of Lesion

• Middle Ear; Conductive
• Mixed loss w/ Inner Ear involvement

Severity of Loss

• Starts as low frequency conductive loss
• Progression toward flatter and more severe CHL
• Mixed loss will show abnormal high frequency bone conduction thresholds
• Carhart's Notch; dip in bone sensitivity at 2kHz, typically bilateral loss

Tympanometry

• Type A or As

Acoustic Reflexes

• Absent reflexes with probe to the affected ear
• If disease is unilateral, contralateral reflex may be present but elevated by the amount of the conductive loss

OAEs

• Absent with a significant conductive loss

Pure Tone Audiometry

• Unilateral or Conductive loss

Speech Audiometry (SRT/WRS/QuickSIN)

• SRT/PTA in agreement
• Word Recognition Scores when intensity can overcome conductive component

Recommendations

• Refer to ENT for imaging and medical management (fusion of ossicles, potential stapedectomy)
• Amplification after medical clearance​