exam 1 Flashcards
Sound is a ______ ______
pressure wave
what is the smallest amount of pressure required to move an eardrum
0.0002 dynes/cm2
Velocity
- The speed of a sound wave
- Impacted by elasticity and density
Wavelength
-Distance a sound wave travels in one cycle
Pure Tones
- A single, isolated pitch
- “simple sound”
- very rare
- can be heard from tuning forks and audiometers
Complex sound
- Two or more pitches combined
- so pretty much everything else
Those who wear hearing aids sometimes report that on __________ days they are able to hear ___________.
- humid/muggy
- more clearly
Longitudinal waves
-Movement in one direction
Transverse waves
-Perpendicular movement
________ and _______ are points of maximum displacement
Compression
Rarefaction
The number of cycles per second is called:
Hertz
Hertz
Pitch/frequency
Subsonic:
-Less than the speed of sound
Supersonic:
-Greater than the speed of sound
Other types of sound
- Infrasonic
- ultrasonic
Decibels:
- The amplitude of the cycles
- loudness
Humans hear from __ Hz to _____ Hz but we only test to ___ Hz
- 20Hz
- 20,000 Hz
- 8K Hz
What is the range of Hertz needed for human speech?
Between 500 Hz and 4000 Hz
The period of sound:
- Hertz/frequency/pitch
- cycles per second (cps)
Low frequency sounds = _____ period
longer
High frequency sounds = _____ period
shorter
The human ear is most sensitive from :
125 to 8000 Hz
needs the least dynes per cm2
dB SPL=
- Sound Pressure Level
- used in measuring hearing aid performance/function
- 0.0002 dynes/cm2
dB IL =
- Intensity Level
- used in electrical measurements/calibration of audiometers
- watts/cm2
dB HL =
- Hearing Level
- used on hearing tests and audiograms
- each frequency calibrated to the human zero
dB SL =
- Sensation Level
- refers to the level above threshold
- used for speech recognition testing
dB nHL =
- Neural Hearing Level
- used in auditory brainstem testing
- most often referred to as eHL (estimated hearing level)
zero on an audiogram is…
NOT the absence of sound, it is the typical lowest hearing level
What is the logarithmic scale used for measuring hearing?
dBHL
The human ear can detect ________
0-140 dBHL
once you reach above this level it results in instantaneous hearing loss
True or false:
Some people can hear negative dB levels.
True
If needed, what is the max level of dB that can be tested?
120 dBHL
What are the measured aspects of an audiogram?
- frequency vs intensity
- air conduction vs bone conduction
- left ear vs right ear (symmetrical vs asymmetrical)
- masked vs unmasked
An audiogram is an _____ graph in which frequency and pitch goes up by ______ on the ___ axis and loudness and intensity goes up by ____ on the ___ axis.
- inverse
- octaves
- x axis
- tens
- y axis
Name the types of hearing loss
- Conductive
- Sensorineural
- Mixed
- unilateral/bilateral
- symmetrical/asymmetrical
- Vibrotactile
- Auditory Neuropathy
Conductive hearing loss:
- outer or middle ear “conducts” sound to inner ear
- can be due to wax, infection, no outer ear, etc.
Sensorineural hearing loss:
- dealing with the cochlea (sensory)
- dealing with the nerves (neural)
Vibrotactile hearing loss:
-sound that you can physically feel because it is so loud and low
Air conduction audiology symbols:
0=right ear (right round) unmasked X= left ear unmasked ∆= masked right ac □= masked left ac ac=air conduction
Bone Conduction audiology symbols:
= left ear unmasked
(open end points to the ear it represents)
[ = masked right bc
] = masked left bc
a symbol with an arrow attached means NR (no response)
Masking:
-Using noise to occupy one ear while testing the other
more symbols:
s = sound field (speakers) both ears working together R= aided right ear only L= aided left ear only CI= cochlear implant
Degrees of hearing loss as described on an audiogram:
- flat vs sloping
- cookie bite (high on the ends low in the middle)
- ski slope (very steep)
- reverse slope (very rare)
- high frequency (looks like a flipped letter L)
Articulation index: most speech frequencies occur between ___ and __
1K and 4K
Acoustics:
-The study of sound and perception
Noise:
-Any unwanted/interfering sound
Signal:
-The sound you want to listen to
Reverberation:
- Echo
- the amount of time it takes a sound to decrease by 60 dB after the source has stopped, measured in seconds
Signal to noise ratio S/N:
-Volume of the signal vs the volume of the noise
General noise tends to carry a lot of ___ _______ which “mask” softer ____ ____ speech sounds.
- low frequencies
- high frequencies
ANSI standards of noise:
_
ASHA standards of noise:
_
Sound level meter:
- has 3 scales for different purposes
- most common is the A scale
- measures how loud a room is
Noise sources:
-internal vs external
Give an example of an internal noise source:
-talking, moving, tapping, writing, music, lighting
Give and example of an external noise source:
-traffic, wind, hallway, construction
Inverse square law:
-signal decreases by 6dB for every doubling of distance
ANSI standards of signal noise ratio:
+15 dB S/N for hard of hearing students
+6 to 12 dB S/N for hearing students
Echo:
-created as sound that bounces off of hard surfaces and interact with the size and shape of a room
Things to consider in a room:
-diameter, shape, features, internal and external sounds
The human ear forms between ___ and ___ weeks of gestation.
3 and 37 weeks
The human ear is functional at ___ weeks.
20 weeks
True or false: the ear does not grow after birth
true
The cochlea is the size of a ____
pea
The human ear contains _____ ____ from all other body systems.
representative tissue
Genetic info:
Our genes contain __ chromosomes (__ from each parent)
__ sets are autosomal and _ set determines the gender
46
23
22
1
A ____ percentage of genetic material is redundant.
large
__% of human DNA is identical
99
Chromosomes live in the _____ of each cell
nucleus
About __ in every ___ people carry a recessive genetic mutation for hearing loss
1 in every 7 ppl
Parts of chromosomes:
The __ arm is the long piece of the chromosome and the __ arm is the short piece.
DNA strands are made of __ bases.
q
p
4
What are the 4 bases of DNA?
Adenine
Guanine
Cytosine
Thymine
Info about the Outer Ear:
The Pinna has a natural resonation of about ____Hz.
Shape helps to localize sound to the ____ ___.
The ear canal is approx. ____ cm.
The ear canal is actually ___ shaped.
Outer 1/3 is ___ and ____
Inner 1/3 is ____
- 1500 Hz
- inner ear
- 2.5 cm
- s
- skin and cartilage
- bone
Info about the Middle Ear:
The tympanic membrane has __ layers which are:
The adult size of the membrane is about ___mm.
Pars___ and Pars ___
Ossicles: ____, ___ and ____.
The ossicles add about ___ dB before transferring into the cochlea.
The muscles: _________ and ____ known as the ____ ____ __ .
The middle ear space is surrounded by ____ bone.
- 3
- skin, fiber, mucous
- 9mm
- Pars tensa and Pars Flaccida
- Malleus, Incus and Stapes
- 27dB
- tensor tympani and stapedius
- acoustic reflex arc
- porous
The Eustachian tube changes from infancy to early teen in what way?
-it changes angle, going from horizontal to having more of a slope
Efferent sounds:
Brain to ear
descending pathway
Afferent sounds:
Ear to brain
ascending pathway
Acoustic Reflex Arc:
efferent vs afferent sounds
Info on the Inner Ear:
The _____ deals with hearing
The ______ ____, ____ and _____ deal with balance. These are a part of the ________ system.
The ______ connects these two portions.
The internal auditory canal is made up of the __ ___, ____ ___, ____ and _____.
- Cochlea
- semicircular canals, utricle, saccule
- vestibular system
- vestibule
- VIII nerve, facial nerve VII, artery and veins
The cochlea is a snail shaped bony structure that has _____ turns.
2 1/2
The cochlea has 3 layers called _____.
Scala
Scala vestibuli:
- top layer
- filled with perilymph
Scala tympani:
- bottom layer
- filled with perilymph
Scala media:
- middle layer
- filled with endolymph
______ is a narrow opening at the apex that connects scala tympani and scala vestibuli.
-Helicotrema
The Basilar Membrane supports the ____ __ ____ and is _____ at its base and ______ towards its apex.
- Organ of Corti
- stiffer
- flexible
The Basilar Membrane changes its width from its base (________) to its apex (_______).
- .08-.16mm
- .42-.65mm
The ear is very ___ ___ which means:
- tono-topic
- different frequencies interact with different parts of the cochlea which is a long curled tube that is wide at the base and thin at the apex)
The scala media is separated from the scala vestibuli by ___________ _________ (top).
-Reissner’s membrane
True or false: the Organ of Corti only has inner hair cells/
-False
It has inner and outer hair cells
The number of outer hair cells of the Organ of Corti is _______ in __ rows.
- 12,000
- 3
The number of inner hair cells of the Organ of Corti is _________ in ___________.
- 3,500
- a single row
The hairs are basically like a ______________________ and all of the strands attach to the _________.
- frayed end of a rope
- cochlea
The hair grows out of the ________ _________.
-Basilar membrane
Which membrane lays over the top of the hair cells?
-The Tectorial membrane
Which hair cells make contact with the tectorial membrane?
-only the outer hair cells
The inner hair cells are __________.
-Afferent
The outer hair cells are _________.
-Efferent
Sound causes the basilar membrane to move ______________ while the tectorial membrane moves ______________. This motion causes: _____________________.
- in one direction
- in opposite directions
- shearing of the hair cells
Hair cells _______ and either __________ or __________.
- bend
- shorten
- lengthen
The “_____” at the base of the cell opens and allows ______________ which creates ____________.
- Gate
- chemical exchange
- neural signal
Where do the nerves come together to become part of the auditory nerve?
-The Modiolus
Describe the Modiolus:
-The gathering of nerves through the central bony part of the cochlea.
When the VIII nerve meets the vestibular nerve, the nerve cells are now __________.
-Spiral Ganglion
The VIII nerve/vestibular nerve enters the brainstem at the ______________.
-Cerebellopontine angle
In the central auditory system, high and low frequency sounds maintain: _________________.
-Tonotopic fidelity
Info about the Central Auditory system:
40% of transmission stays ___________.
60% of transmission crosses to the __________________.
The CAS codes for ________, ________ and ____________.
- ipsilateral
- contralateral
- timing, intensity and frequency
The process of the Central Auditory system:
Enters…
Transmits….
and then to…
-Enters the central system at the cochlear nuclei
-Transmits to the superior olivary complex (first point of bilateral representation)
-Transmits to lateral leminiscus
(still tonotopic)
What is bilateral transmission thought to help with?
-Hearing in noise
Explain why children who have hearing loss in their right side of the brain struggle more in school:
-This occurs because the sound and info that goes into the right ear travels to the left part of the brain, which deals more with speech processing
The process of the Central System:
Relays to…
Enters…
And then…
- Relays to inferior colliculus
- Enters the medial geniculate body
- Reticular formation in the central portion of the brainstem
What is referred to as the largest “relay station” and what is it sensitive to?
- The inferior colliculus
- Highly sensitive to bilateral stimulation
What is the last “station” before signal travels to the auditory cortex? Where is it found? What is its importance?
- The medial geniculate body
- In the thalamus
- needed for auditory discrimination
What process is thought to regulate selective attention?
-reticular formation in the central portion of the brainstem
Auditory cortex:
Sound enters…
Sound is sent…
- Sound enters the temporal lobes at Heschl’s gyrus
- Sound is sent to the Wernicke’s area
What is the language center of the brain?
-Wernicke’s area
Balance, postural control and stabilization of gaze are all central function of which system?
-Vestibular system
Describe Oscillopsia:
-A condition where visual images oscillate and is caused by a disruption to the vestibulo-ocular reflex
What organs are used to sense linear changes in movement such as acceleration, deceleration, rate and direction?
-The utricle and saccule
What organ(s) monitor the body in space and responds to angular changes?
-The semicircular canals
What is the enlarged area at the base of the semicircular canals?
-The Ampulla
Describe the Cristea:
-Sense organ used for balance
What are Otoliths?
-Small crystals made of calcium carbonate located in the inner ear that are usually free floating
The vestibular nerve:
- Joins the cochlear nerve to become Nerve VIII
- Contains endolymph and perilymph, separated by an endolymphanic duct.
The _______ ___ is an ear anomaly.
-Endolymphanic sac
