Med Audiology Midterm

Outer and Middle Ear disorders

A type B tympanogram can indicate 2 scenarios of measurements. Describe those 2 scenarios and name 1 common disorder associated with each scenario

1. Wax impaction - Tympanic peak pressure not measurable, admittance/compliance (Ytm) not measureable, and small ear canal volume

2. Tympanic membrane perf - Tympanic peak pressure not measurable, admittance/compliance (Ytm) not measureable, and large ear canal volume

What do otoacoustic emissions test for?

It tests for the function of the outer hair cells.

When would an MRI be preferred over a CT scan for evaluating the auditory system?

Superior soft tissue discrimination, lack of ionizing radiation, true multiplanar capability, use of safer contrast agents

When would a CT be preferred over an MRI for evaluating the auditory sysem?

It’s readily available, and is fast. It’s also good at characterizing bony abnormalities (fractures, ossicular disruptions), bony destruction from osft tissue tumors, and bony abnormalities related to congenital hearing loss

What are the disadvantages to using an MRI

Longer scan times, patient compliance required (possibly sedation needed), more limited availability, and increased costs

What are the absolute contraindications to using an MRI?

Cardiac defibrillator, cardiac pacemaker, pacer dependent, metallic foreign body in critical location (like their eye), certain cerebral aneurysm clips

What are the relative contraindications to using an MRI?

Cochlear implant, pregnancy, patient is unstable, patient is combative (consider sedation if the scan is required)

What are two types of subjective audiometric tests?

1. Pure tone audiometry

2. Speech audiometry - Speech Reception Threshold and Speech Discrimination

What are three functions of the pinna?

It funnels sound into the EAM

The pinna resonates at around 4000 Hz and helps with localization

It helps collect sound vibrations near the opening of the ear

List at least 4 characteristics or functions of the external auditory meatus

Sound waves get amplified as it gets funneled down

It has natural acidity that protects the ear canal from infetion

It secretes cerumen to maintain moisture

It transmits sound to the middle ear

What is exostosis and its cause? What’s the theoretical association? What are the treatment options?

A malformation of the external auditory canal where benign bony lumps begin to grow superiorly, anteriorly, and posteriorly.

The cause is due to exposure to cold water and/or cold wind. The theoretical association is that the body forms the bony growths as a protective response to that exposure.

Treatment options - mild - counseling, severe - surgery

What’s the difference between exostosis and osteomas?

The main difference is the causes. Exostosis is caused by cold water/air exposure, osteomas can appear suddenly

What are the causes of a tympanic membrane perforation?

Blunt trauma, forced foreign object (qtip), fluid behind the ear burst

What are the symptoms of a TM perf

Otalgia, ottorhea, hearing loss, tinnitus, dizziness/vertigo

What kind of audiometric results do you expect?

Low FQ Conductive HL up to 60dB HL air-bone gap. No TPP/YTM but large canal volume

What are the treatment methods for TM Perf?

Refer to ENT, waitful watching (wait to see if it heals on its own, surgical tympanoplasty if not healed