Hearing loss Flashcards
Ringing, buzzing, or “crickets” in the ears describes this manifestation of hearing loss.
tinnitus
T/F Conductive hearing loss involves the inner ear/8th CN
F - sensorineural
What are 5 causes of conductive hearing loss?
How can you tx them
- cerum impaction (most common) - irrigate, ear drop, instrument
- swelling of EAC - topical meds
- TM perforation - surgery
- Middle ear fluid - most common cause of hearing loss in kids - abx/myringotomy tubes
- ossicular chain abnormalities
What are 5 causes of SNHL that involve injury to hair cells in the COCHELA/neural elements innervating the hair cells?
- persistent noise exposure
- presbycusis (age related change in CN 8)
- genetics
- infections/postinflam process
- Tumor growth (acoustic neuroma) along CN 8
What does pure-tone audiometry test?
What does 0-db level mean?
T/F the higher the threshold, the better the patient’s hearing (e.g threshold lower than 25db is considered abnormal)
- hearing levels
- normalized to young, healthy adults (doesnt mean abscence of detectable sound)
- F. higher than 25 is abnormal
What type of conduction? Ability of external and middle ear to transmit sound to cochlea.
What type of hearing loss?
Air conduction. Relates to conductive hearing loss (barrier to sound transmission)
What is the air-bone gap? What type of hearing loss is this associated with?
Gap between the air and bone conduction thresholds on the audiogram. Seen with conductive hearing loss
What type of hearing loss can be diagnosed if air conduction and bone conduction thresholds are equal (eg. no air-bone gap) but >25db
SNHL
What does the speech discrimination test evaluate?
What is normal?
- ability to understand spoken words and assess fcn of auditory division of CN 8
- 90%-100% is normal
What does tympanometry evaluate?
TM mobility and response to pressure changes in the EAC.
Tympanometry with greatest compliance where P(ear canal) = Patm
Peak at 0
Type A: EAC is patent and middle ear and TM are healthy
Max TM mobiltiy when pressure in canal is atmospheric
Tympanometry with compliance of TM greatest at pt where pressure in canal is 200mm of water below Patm (L shift)
Type C: Inefficient eustachian tube fcn with persistent neg pressure in the middle ear.
Retracted TM secondary to eustachian tube dysfunction
Tympanometry with poor compliance at any freq (no peak)
Type B: Suggests TM immobilization by fluid in middle ear or TM perforation.
- If audiogram shows conductive hearing loss, but it’s not apparent on physical exam, what does this imply?
- Etiology?
- Tx
- Ossicular chain problem (otosclerosis)
- hereditary - bony prolif w/in temporal bone at footplate of stapes –> fixates ossicular chain
- Stapedotomy
This is the most common form of hearing loss. What’s the most freq cause?
Is it teratable with surgery?
SNHL, prebycusis
No - but cochlear implants and devices may help if profound.
