Exam 1 Flashcards
what pathway has good temporal resolution compared to other cells higher than the cochlea nuclei?
lateral lemniscus (LL)
this part of a hearing aid increases the amplitude of the electrical signal from the microphone
amplifier
the HA’s output to a 90 dB SPL input
OSPL90 (output sound pressure level 90)
the number of cycles completed per second
frequency (Hz)
the difference, in dB, between the input level of an acoustic signal to a hearing aid and the output level of the hearing aid
gain
what are the two parts of the IE?
- cochlea
- vestibular system (semicircular canals, saccule, utricle)
amplitude of lower simple frequencies are best represented at the base or apex of cochlea?
apex
what are the three ways hearing aid gain can be defined?
The difference between unaided and aided hearing levels.
The difference between input level and output level.
The difference between input level to a HA and output of a HA.
the tendancy to remain unchanged to any change in its state of motion
inertia
as the object vibrates away from the vibrating object, air pressure increases above the static air pressure at any one location
condensation
T/F: both IHCs and OHCs send auditory neural information to the CNS?
TRUE
but IHCs are primary afferent (send) nerves and OHCs are primary efferent (receive) nerves
T/F: modern hearing aids usually have two microphones
true
what are the two types of receivers?
receiver in the hearing aid & receiver in the canal (RIC)
frequency is directly related to both the quality of _______ (intelligibility) and the _______ (audiblity)
sound
loudness
Which hair cells are efferent?
OHC
when a neuron is not sending a signal due to insufficient input
resting potential
spongy bone which spiral ganglion cells and cochlear nerve are situated
modiolus
mass can cause “_____” while spring can cause “______”
inertia
elasticity
what are the four major properties of sound?
- frequency
- amplitude
- phase
- time
What are the 3 fluid filled scalea in the cochlea?
- scala vestibuli
- scala tympani
- scala media
A HA gain is generally matched to the degree of _____ _____ and the ______ ______ of the listener.
hearing loss
dynamic range
T/F: amplitude decays over time
True
as the object vibrates toward the vibrating object, air pressure decreases below the static air pressure at any one location
rarefaction
What is the anatomy of the ME?
tympanic membrane, ossicles, ET, oval and round windows
what covers the entire outer wall of the scala media?
stria vascularis
a microphone designed to respond primarily to sounds originating from in front of the wearer and helps to improve signal-to-noise ratio
directional
what pathway is involved in the acoustic startle relfex?
lateral lemniscus (LL)
this part of a hearing aid converts the amplified electrical signal back to acoustic sound
receiver
what part of the central auditory system’s functions is 1:1 representation of tonotopic organization of hair cells
cochlear nucleus complex (CNC)
_____ coding is that nerve fibers that innervate hair cells at the apex are in the middle of the nerve bundle, while fibers towards the base make up the outside of the nerve bundle
frequency coding
air molecules next to those initially moved are moved back and forth (horizontally) through stages of condensation and rarefaction is what type of wave
longitudinal
T/F: frequencies going through the cochlea will stimulate all regions
TRUE
however, the specific frequency will have a higher amplitude/displacement
what types of microphones are there?
directional
omnidirectional
what are the four main components of a hearing aid?
- microphone
- amplifier
- receiver
- battery
amplitude of higher simple frequencies are best represented at base or apex of cochlea?
base
what does the processor of a hearing aid do?
controls the whole hearing aid system
what are the two perspective HA fitting procedures?
NAL-NL1 and 2
Desires Sensation Level (DSLl/DSL[i/o])
what is scala media filled with?
endolymph
are there more IHC or OHC?
OHC
12,000 OHCs vs 3500 IHCs
the range of intensities from the softest sounds we can hear to the loudest sounds we can tolerate.
dynamic range (window of hearing)
why is an ear mold important for a traditional BTE HA (3 reasons)
Deliver the amplified sound from HA to the ear
Couple the HA to the wearer
Prevents acoustic feedback
Which hair cells are afferent?
IHC
low frequency needs (higher/lower) stiffness and (small/larger) mass
lower stiffness and larger mass
IHC have how many sterocilia?
40
IHC or OHC primarily receive neural signals from the CNS?
OHC
who are the ideal candidates for hearing aids?
individuals with moderate to severe hearing loss
when a neuron is at ‘rest’, the inside of the neuron is _______ relative to the outside
negative
what part of the central auditory system’s function is lateral inhibitory network helps sharpen the neural representation of spectral information in a complex sound field
cochlear nucleus complex (CNC)
what part of the central auditory system’s primary functions are;
1. 1:1 representation of tonotopic organization of hair cells
2. lateral inhibitory network helps sharpen the neural representation of spectral information in a complex sound field
cochlear nucleus complex (CNC)
this part of a hearing aid picks up input acoustic sound and coverts them into electrical signals
microphone
a microphone that is equally sensitive in all directions
omnidirectional
what are the two function of the central auditory system?
- preserving information
- processing information
what measures are typically included for a quality control of HA?
- Gain of a HA
- Frequency response of a HA
- Output sound pressure level 90 (OSPL90)
- Compression (attack time and release time)
- Distortion limits
- Directional microphone positioning
- Tele-coil response
this part of the hearing aid provides power to drive the amplifier
battery
IHC or OHC primarily send neural signal to the CNS?
IHC
what are the three major functions of the ME
- Convert acoustic into mechanical energy through oval window
- Impedance mismatching
- Pressure equalization via ET
when ion channels of the hair cells open and allow potassium and calcium into the hair cells is this depolarization or hyperpolarization?
depolarization
Which hair cells are shaped like a ‘u’?
IHC
what is the second structure to receive auditory inputs from both ipsilateral and contralateral cochlear nuclei?
inferior colliculus (IC)
an electronic device to convert one form of a signal to another (i.e., electric to acoustic or acoustic to electric)
transducer
coded by discharge rates, number of nerve fibers, & number of neurons stimulated along the basilar membrane
amplitude coding
What is the first structure to send neural signal to contralateral sites?
cochlear nucleus complex (CNC)
True/False: the cochlear nucleus complex sends projections only contralaterally
FALSE
it sends projections both contra and ipsilaterally, however it is mainly contralaterally
Which hair cells are shaped like a ‘v’ or ‘w’?
OHC
what are the major functions of the outer ear?
- Protection of middle ear from foreign bodies and changes in humidity and temperature
- Sound localization via increase in loudness and increase in resonance properties of pinna and ear canal
Special circuit that enhances telephone communication or allows compatibility with loop systems using electromagnetic field
telecoil
this pathway receives tonotopic information from ipsilateral IC
medial geniculate body (MGB)
time a HA takes to put prescribed gain when input level is soft
release time
HA fitting perspective where it is designed to maximize speech intelligibility at their most comfortable loudness level with equal loudness across frequencies
NA:-NL1 and 2
this receives input from ipsilateral and contralateral fibers to maintain tonotopic representation and retain function plasticity beyond early years
primary auditory cortex (A1)
the amount of vibratory displacement from the resting position
amplitude
the amplifier determines the “_____” of a hearing aid
gain
where are the IHC and OHC located?
Organ of corti
The tips of the tallest cilia of OHC are in contact with what structure?
tectorial membrane
OHC have how many steriocilia?
150
what is the difference between 100 Hz and 1000 Hz?
100 Hz has 100 complete cycles per second while 10000 Hz has 1000 complete cycles per second
an ability of the object to return to a starting state after it is deformed or moved by the inertia
elasticity
what is the first structure to receive auditory inputs from both ipsilateral and contralateral cochlear nuclei?
superior olivary complex (SOC)
what should the selection of HA be based on (4 things)?
- gain and output needs
- configuration of audiogram
- HA features (i.e., # of channels, noise reduction, feedback suppression, and patient preferences)
- amplitude compression characteristics (i.e., dynamic range, maximum comfort level, and uncomfortable loudness level)
amplitude of basilar membrane vibration is different at different locations along the organ of Corti, depending on the frequency and level of the input stimulus
tonotopic organization
what pathway has a relay for transmission of auditory info to primary auditory cortex?
medial geniculate body (MGB)
high frequency needs (higher/lower) stiffness and (small/larger) mass
higher stiffness and smaller mass
the source of sound is ______
vibration
what are the three membranes in the cochlea?
- basilar
- reissner’s
- tectorial membrane
what are the four critical areas from the audiological management of adult hearing impairment to be addressed for every HA fitting?
- HA selection
- quality controls of HA
- HA fitting
- Verification of the fitting
air molecules next to those initially moved are moved up and down (perpendicularly) is what type of waves
transverse
time a HA takes to put less gain when input level is already high
attack time
what is the role of the stria vascularis?
- produces endolymph
- provides oxygen via it’s rich blood supply to the cochlea
Tallest hair cells are called?
kinocilium
how many rows do IHC and OHC have?
IHC=1 row
OHC=3 rows
What is scala vestibuli and scala tympani filled with?
perimlymph
this pathway influences the direction and maintenance of attention
medial geniculate body (MGB)
HA fitting perspective to make sounds comfortably loud across all hearing levels and all frequencies rather than equally loud
Desired Sensation level (DSL [i/o])
How long is the cochlea?
30-35 mm
what are the modes of operation for the OE, ME, & IE?
OE: air
ME: mechanical
IE: mechanical, hydrodynamic, electrochemical
what is the function of the OE?
localization, amplification, protection
what is the function of the ME?
impedance matching
pressure equalization
selective oval window stim
what is the function of the IE?
filtering distribution
transduction
Which of the following is NOT true regarding the CNC?
A. sends majority of neural information ipsilaterally
B. it primarily performs spectral (frequency) processing
C. it holds 1:1 tonotopic organization
D. it has two major divisions: dorsal and ventral
A
B is primary function
which of the following is true?
A. efferent fibers are more related to IHCs (supposed to be OHC)
B. afferent fibers are more related to OHCs (supposed to be IHC)
C. central system incorporates both monaural and binaural information
D. ventral is the same as “posterior”
C
which of the following is NOT true about neural reactions of hair cells?
A. depolarization is the same as polarization
B. potassium and calcium are two major ions
C. scala media has +80mV at resting potential
D. hair cells have -70 mV at their resting potential
A
Which of the following is NOT true?
A. HA can be optimally used for individuals with profound hearing loss
B. HA is primarily an amplifier
C. One of the main parts of HA includes a battery
D. There are two types of microphones directional and omni-directional
A
Which of the following is NOT true about gain?
A. Difference between unaided and aided hearing thresholds
B. Gain is the same as dynamic range
C. difference between input and output level
D. amount of gain that HA provides is matched to the degree of hearing gloss
B
Which type of hearing aid eliminates wind noise the most?
- Open fit BTE with a RITA
- ITE
-ITC
-CIC (microphone is deep inside the ear)
CIC
which type of hearing aid faces the issue of an occlusion effect the most?
-ITE
-ITC
-CIC
-Traditional BTE
CIC
Which type of hearing aid requires an ear mold?
- CIC
- Open fit BTE with a RITC
- Traditional BTE
- ITE
Traditional BTE
Which type of hearing aid may generate the least acoustic feedback?
-ITE
-CIC
-Traditional BTE with an ear mold
-Open fit BTE with a RITC
Traditional BTE with an ear mold
Area difference from the tympanic membrane to the stapes footplate compensates the impedance mismatch about __ dB
25 dB
The ossicles react like a lever system, compensating the impedance mismatch about ___ dB
2.3 dB
The buckling of the Umbo compensates for the impedance mismatch of about __ db.
6 dB
You can only measure _____ ______ when the external stimulus is absent
resting potential
The vibratory wave-motion of the basilar membrane is a _____ wave.
traveling
This converts mechanical energy to electrochemical (i.e., neural) energy.
cochlea
The tip links play a crucial role in the transduction of the movement of the stereocilia into neural activities that take place in the cells.
What structure?
Organ of Corti
In order for frequencies below 100 Hz to be heard, the basilar membrane theoretically should have ___ stiffness and ___ mass
low stiffness
large mass
What is “predominantly” used by the auditory system to encode frequency information?
Place theory or topographical organization
What is the first structure to receive information?
Superior CNC
What is the second structure to receive information?
Inferior CNC
The primary structure for processing interaural time and level differences is the ?
superior olivary complex (SOC)
