Exam 4 Flashcards
Peripheral Auditory System
Outer ear to auditory nerve
Central Auditory System (Includes…)
Cochlear nucleus to auditory cortex in the temporal lobe
The auditory nerve terminates between the _____ and the _______.
pons & medulla (ponto-medullary junction)
ACSLIM
Auditory nerve (peripheral)
Cochlear nucleus
Superior olivary complex
Lateral lemniscus
Inferior colliculus
Medial geniculate body
(then into the temporal lobe)
The minimum age for a central auditory processing disorder (CAPD) diagnosis is __, and it takes until __ for the system to completely mature.
7, 13
The ____________ is the first site of binaural interaction, and the ___________ is the second.
- Superior olivary complex
- Inferior colliculus (bigger)
Number of nerve fibers in each branch of the auditory nerve
- Cochlear: 30,000
- Vestibular: 20,000
The basal turn (outer core) of the cochlea carries _____ frequency information; the apical turn (inner core) carries _____ frequency information.
high; low
The auditory nerve exits the middle ear through the ______.
IAM (Internal Auditory Meatus)
2 nuclei of the cochlear nucleus:
- Dorsal: low frequencies (fed by apical [ascending] fibers)
- Ventral: high frequencies (fed by basal [descending] fibers)
Binaural interaction in the SOC is responsible for _________ and _________.
localization, stapedial reflex function
2 primary nuclei of the SOC
- Medial superior olive: low frequencies
- Lateral superior olive: high frequencies
2 nuclei of the lateral lemniscus
- Dorsal: low frequencies
- Ventral: high frequencies
What is the brachium?
Major tract that connects the inferior colliculus and the medial geniculate body
3 nuclei of the medial geniculate body
- Dorsal: low frequencies
- Medial: mid frequencies
- Ventral: high frequencies
The auditory cortex is located in the _________ lobe
temporal
3 important cortical areas in the auditory cortex
- Primary auditory area
- Association/Wernicke’s area (#22)
- Insula
Which artery feeds the medial 3/4th of the brain?
Anterior Cerebral Artery
Which artery feeds the lateral 3/4th of the brain, including Heschl’s gyrus, insula, & parietal areas?
Middle Cerebral Artery
Another name for an 8th nerve (auditory nerve) tumor is an ___________.
acoustic schwannoma
Click ABR and TEOAEs provides information about the hearing status between ____ and ____ Hz only
1000 and 4000
ABR only tests functioning up to the level of the _____________.
lateral lemniscus
ABR, OAE, and tympanometry are all _________ tests of hearing
objective
ABR uses __ electrodes
3 (one on the top of the head and one behind each ear/on earlobes
Where do the 5 ABR waves come from?
I and II: auditory nerve
III: cochlear nucleus
IV: SOC
V: lateral lemniscus
_______ of waves is a useful metric that can be used clinically, while ________ of waves is not.
latency; amplitude
What are the normal values for absolute latency for ABR waves I, III, and V at 60-70 dB HL (24 months +)?
2 ms for wave I
4 ms for wave III
6 ms fo wave V
(interpeak values are 2 ms between I-III and III-V; 4 ms between I-V)
Before 24 months, time values for ABR waves will be significantly _______ because the auditory pathways haven’t matured.
higher
In a patient with a cochlear lesion or conductive hearing loss, ABR absolute latencies will be_________, and interpeak latencies will be _________.
prolonged/abnormal; normal
In a patient with a neural lesion, ABR absolute latencies will be_________, and interpeak latencies will be _________.
abnormal; abnormal
Interpeak latencies in ABR indirectly give us information about what?
Conduction time in the neurons.
What are Evoked Otoacoustic Emissions (EOAEs)?
Low-level sounds produced in the cochlea to an evoking stimulus. Are recorded from the external ear canal using a sensitive, low-noise microphone.
Transient Evoked OAEs vs. Distortion Product OAEs
- TEOAEs: clicks or tonebursts
- DPOAEs: pairs of puretones (f1 & f2)
Lateral & Medial OCB
- Stimulation of the MOCB causes a _________ in the endolymphatic potential, hair cell potential (CM) and the discharge rates (action potentials) of afferent neurons.
- Stimulation of the LOCB causes __________ in the endolymphatic or the cochlear microphonic potential and a ________ in the discharge rates of afferent neurons.
- decrease
- no change; decrease
What are the average TEOAE levels for newborns, adult females, and adult males?
- Newborn: 18-20 dB SPL
- Adult female: 10-15 dB SPL
- Adult male: 8 to 13 dB SPL
OAEs tell you about the functioning of the ______.
OHCs
OAEs are _______ in patients with conductive hearing loss.
absent
Formula for suppression in dB SPL
TEOAEs (quiet) - TEOAEs (noise)
In OAE screening, response amplitude should be at least __ dB higher than the background noise.
6
Presbycusis
Hearing loss that comes with aging
________ aspects of speech are affected in CAPD patients
Temporal (prosody/intonation/rhythm)
Results of studies 1 & 2
- Amplitude of OAEs in quiet doesn’t change with age (when you control for hearing loss)
- TEOAE suppression (MOCB/efferent system) decreases with age, leading to difficulty hearing in noise
