Audition Anatomy
What two parts of the body does the Eustachian tube connect?
Communicative port between nasopharynx and middle ear cavity
What type of hearing loss are cochlear implants for?
Profound sensorineural hearing loss
What does ROM stand for?
Range of motion
What might tongue fasciculations indicate?
Damage to LMNs
What is the role of cerumen (ear wax)?
Protects ear canal from drying out and prevents intrusion of insects/other material
Where on the cochlea responds to high versus low frequencies?
Base: stiff → responds to high frequencies
Apex: flexible → responds to low frequencies
What is the location of damage for sensorineural hearing loss?
Inner ear components (e.g., cochlea, hair cells, etc)
Why do we do an oral mech exam?
Information about structural integrity of oral mechanism
Information about neurological underpinnings of condition
What would you expect to see in DDKs if someone had basal ganglia damage secondary to PD?
Excessively fast or variable rate
What is a speech banana?
A speech banana represents the range of frequencies and intensities of sounds that are used in human speech; it serves as a visual aid for understanding which speech sounds might be audible or inaudible to someone with hearing loss at different pitches and loudness.
Name the three smallest bones in the ear (and the body).
Malleus (hammer)
Incus (anvil)
Stapes (stirrup)
What is one general role of the inner, middle, and outer ear?
Outer: sound collection (helps with sound localization by funneling sound), sound protection (shields inner parts of ear)
Middle: sound amplification (enhances sound vibrations from outer ear), pressure equalization (maintains balanced air pressure on both sides of eardrum via eustachian tube)
Inner: sound conversion (converts sound vibrations into electrical signals), balance sensation (senses head movement and position)
Name the five tools you need to conduct an oral mechanism exam.
Gloves
Pen light
Tongue depressor
Stop watch
Mirror
What would you see in the face if someone had UMN damage?
Spasticity or tension
What are you looking for when you examine dentition?
Malocclusion, missing, or false teeth may impact tongue placement for speech sounds and oral prep phase of swallowing
What are the three tools and/or methods used to evaluate the inner, middle, and outer ear?
Inner: otoacoustic emissions testing
Middle: tympanometer
Outer: otoscope
Name the four types of energy that sound is translated into in the outer ear, middle ear, cochlea, and auditory pathway.
Outer ear (acoustic energy): collect and amplify sound, aid in localization
Middle ear (mechanical energy): impedance matching
Cochlea (hydraulic energy): frequency and intensity analysis
Auditory pathway (electrochemical energy): complex signal processing
Name six (out of eight) parts of the oral mechanism you should examine.
Face
Mandible
Dentition
Lips
Tongue
Hard palate + velum
DDK
Voice
What might air escape through lips on cheek puff mean and what else might it cause functionally?
Labial weakness (which may cause drooling and difficulty with bilabials /p/, /b/, /m/)
Describe the development of the eustachian tube and why it leads to more ear infections in children.
Children = more horizontal (allows bacteria and fluid from the nasopharynx easier access to the middle ear, particularly when a child is lying down)
Adults = points downward
Name one problem that can occur in each part of the ear (inner, middle, and outer) and one symptom of each problem.
Inner ear:
Sensorineural hearing loss (difficulty hearing high-pitched sounds, tinnitus)
Meniere’s disease (vertigo, tinnitus)
Middle ear:
Otitis media (ear pain, fluid drainage)
Tympanosclerosis (ear fullness or pressure, reduced eardrum mobility)
Outer ear:
Perforated eardrum (vertigo, tinnitus, buzzing, clicking, fluid drainage)
Name the three ways the middle ear performs impedance matching (and amount of gain each provides).
1. Area ratio: pressure can be increased by decreasing area over which force is distributed, area ratio between tympanic membrane (55 mm2) and oval window (3.2mm2) provides 25 dB gain
2. Lever action: length and positioning of ossicular chain creates lever that provides 2 dB gain
3. Buckling effect: tympanic membrane buckles > boost sound by making ear's bones move with more force > helping you hear sounds more clearly, provides 4 dB gain
Describe four tasks we do with three different parts of the oral mechanism.
Face: Ask patient to raise eyebrows and smile.
Mandible: Ask patient to open and close jaw with resistance and move jaw side to side.
Dentition: Task: Ask patient to bite together.
Lips: Ask patient to pucker, smile, and puff cheeks up with air while clinician squeezes them.
Tongue: Task: Ask patient to protrude, retract, lateralize, elevate, and depress tongue.
Hard palate and velum: Tasks: Ask patient to say “ah”, puff up cheeks with air while clinician squeezes them, and hold out “ooh” with mirror beneath each nostril.
DDK: Task: Ask patient to peform alternating motion rates (AMRs; “puh-puh-puh”, “tuh-tuh-tuh”, “kuh-kuh-kuh”) and sequential motion rates (SMRs; “puh-tuh-kuh”) as quickly and accurately as possible.
Voice: Ask patient to sustain “ah” as long as they can, pitch glide from bottom to top of range, and hold out “s” and “z”.
A child comes in with hypernasality. What are the tasks you would do to test what the cause is?
Presence of nasal emissions: mirror under nose during vowels
Lack of velopharyngeal closure: air escape through nose on cheek puff
Presence of submucous cleft: check for blue-ish tint of palate
What are five different voice abnormalities you are listening for during an oral mech exam and what might they indicate?
Breathy voice may indicate incomplete glottal closure
Strained voice may indicate vocal hyperfunction
High s:z ratio may indicate reduced breath support
Truncated pitch range may indicate limited laryngeal function
Nasal resonance may indicate velopharyngeal dysfunction