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Flashcards in Hearing loss and otology Deck (16)
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How to recognize conductive hearing loss on an audiogram

Bone conduction thresholds are in normal range, but air conduction thresholds are decreased (air bone gap)


How to recognize sensory hearing loss on an audiogram

Changes in pure tone hearing thresholds


Conductive hearing loss

Disorders of the external ear canal, tympanic membrane, and middle ear ossicular chain that impair the transmission of sound (sound conduction) to the cochlea.


Sensory hearing loss

Involves the sensory transduction apparatus within the cochlea (usually loss of hair cells)


Neural hearing loss

Loss involves disorders of the 8th nerve and central auditory pathways. The inner hair cell is often considered part of the neural component as it is directly linked to the auditory nerve. Neural hearing loss typically manifests as changes in word recognition scores or the clarity of hearing.


Common types of pathology underlying sensory hearing loss

Hair cell loss (most common)
Endolymphatic hydrops
Loss of endocochlear potential



A cause of conductive hearing loss


Causes of conductive hearing loss

Otitis media (ear infection)
TM perforation
Congenital aural atresia


Causes of hair cell loss (sensory)

Presbycusis (age-related changes; higher frequencies most affected)
Noise trauma (preventable; chronic and acute)
Ototoxicity (aminoglycosides, chemo; treat with ASA and antioxidants)
Genetic factors


Most common causes of neural hearing loss

8th nerve tumors
Auditory neuropathy
Multiple Sclerosis


Genetics of hearing loss

50% are genetic
70% of the genetic cases are non-syndromic
75% of the non-syndromic cases are AR
50% of these AR cases involve mutations in connexin 26


Endolymphatic hydrops

(Meneire’s disease)
Endolymph compartment of inner ear is expanded
Episodes of vertigo, hearing loss, tinnitus
Unknown cause


Causes of loss of endocochlear potential

Issues with metabolism or blood supply of inner ear

Suspect vascular dysfunction/vasculitis, metabolic causes, or immune system-related disorders


How to recognize neural hearing loss on an audiogram

Often asymmetric (only one ear affected)
Low word recognition score in one ear


Vestibular Schwannoma and treatment

(Acoustic Tumor)
6% of all intracranial tumors
Can cause neural hearing loss

Treatment: observation (in older people when small), surgical resection (if larger), stereotactic radiosurgery (focused radiation treatment can control growth of them when smaller)


Treatment of sensorineural hearing impairment

Air conduction hearing aids (mainstay of treatment)

Implantable hearing aids (being researched and used in Europe; invisible hearing)

Cochlear implants (electrically stimulated inner ear; used when all hair cells are gone)

Assistive listening devices

Speech and language training (in a child esp)