Audition Flashcards
Through hearing we can detect what three sound attributes?
- Complexity
- Intensity
- Frequency
What is sound?
Sounds are produced by ____ objects - vibrations ____ the surrounding ____, creating ____ changes
vibrating
displace
medium
pressure
What is the speed of sound in air?
343 mts/sec
Define:
1. Frequency
2. Amplitude
3. Complexity
- Number of complete cycles per time unit, perceived as pitch
- Magnitude of pressure change, perceived as loudness
- Frequency composition, varies from a pure tone to a mixture of frequencies, perceived as sound quality
The human ear recognises frequencies between what Hz??
20 and 20,000 Hz
What frequencies are defined as infrasound and ultrasound?
Infrasound = frequencies below 20Hz
Ultrasound = frequencies above 20kHz
Fill in the gaps about sound perception…
1. The auditory system can detect changes in a___ p_____ across time in a frequency specific manner
2. Human ears can perceive each individual f________, and its a_______ v________, independently
3. Sound perception is only the b______ of auditory experience
4. The brain receives the information of sound d_______ and assigns m______ to it
- Air, pressure
- Frequency, amplitude, variation
- Beginning
- Detection, meaning
What are the three sections the human ear is divided into?
Outer, middle, inner ear
The outer ear ____ and ____ sound ____
Captures
amplifies
waves
The middle ear a____ and t____ v____
Amplifies and transmit vibrations
What does the inner ear do?
Translates vibrations into neural activity
What are the three parts of the outer ear, and what are their roles?
1. P____ - ____ the ____ from the ____
2. E____ C____ - sounds are ____ into EC
3. T____ M____ - ____ reaches TM - thin ____ that ____ to sounds
- Pinnae - captures, sound, environment
- Ear canal - funnelled
- Tympanic membrane - sound, diaphragm, vibrates
Describe the structure of the middle ear
- A____ filled cavity occupied by o____, the three smallest b____ in the human body: M____, I____ and S____
- Ossicles vibrate in reponse to t____ vibration
- Amplify and t____ sounds to i____ ear (oval window)
- Air, ossicles, bones, Malleus, Incus and Stapes
- tympanic
- transmit, inner
Describe the structure of the inner ear
- Vibration of o____ w____ sends waves through c____ fluids causing the b____ and t____ membranes to bend, which in turn cause c____ of inner hair cells to b____
- This bending generates n____ activity in h____ cells and a____ nerve
- oval window, cochlear, basilar, tectorial, cilia, bend.
- neural, hair, auditory
What are some critical properties of the basilar membrane and apex for sound perception?
The basilar membrane is roughly 5 times wider at the apex than at its base, and the base is about 100 times stiffer than it is at the apex
Fill in the gaps…
The sound wave moves the 1.e_____ and attached 2.o____ c___. The stapes footplate, in the 3.o___ w____, transfers the vibrations to the 4.p________ compartment (scala vestibuli) and to the inner ear structures. Depending on the frequency, the vibration has a maximum effect (5.r______) at a different point along the 6.b________ membrane, accounting for passive 7.t________ (tone spatial representation).
- Eardrum
- Ossicular chain
- Oval window
- Perilymphatic
- Resonance
- Basilar
- Tonotopy
Define tonotopy
Tones s____ a____
Tones spatial arrangement
How does pressure transmission along the canals work?
- Vibration of the s____ push and pull the flexible o____ w____ in and out of the v____ canal at the base of the c____
- Pressure waves d____ the b____ membrane in a frequency specific manner
- All pressure ends up moving the r____ w____ and d____
- stapes, oval window, vestibular, cochlea
- deflect, basilar
- round window, dissipates
What are the three canals the cochlea is divided into?
1. V____ canal - from o____ w____ to the a____, through which p____ w____ move first
2. T____ canal - from a____ to the r____ w____
3. M____ canal - between v____ and t____ canals and contiains the organ of c____
- Vestibular, oval window, apex, pressure waves
- Tympanic, apex, round window.
- Middle, vestibular, tympanic, Corti
What are hair cells in the ear?
- Cells that s____ the s____ which transduce m____ movement in the cochlea into n____ activity sent to the brain s____
- Some h____ cells also receive input from the b____
- Arranged in f____ rows that run down length of b____ m____
- Each human cochlea has ____ outer hair cells and ____ inner hair cells
- support, stereocilia, mechanical, neural, stem
- hair, brain.
- four, basilar membrane.
- 12,000 outer HCs and 3,500 inner HCs.
What is the tectorial membrane?
____ on one end, ____ into the ____ canal
Floats above ____ ____ cells and touching ____ ____ cells
Vibrations of the ____ and ____ membrane make ____ bend
Attached, projects, middle
inner hair, outer hair
basilar, tectorial, stereocilia
Outer hair cells do not respond to basilar membrane vibration. How do they receive feedback?
They recieve feedback from the ____ and can make parts of the ____ partition ____.
This makes the reponses of ____ ____ cells more ____ and more sharply ____ to specific ____.
brain, cochlear, stiffer.
inner hair, sensitive, tuned, frequencies
Stereocilia are ____-____ extensions on the ____ of hair cells. Molecular ____ connect the ____ of each cilia to neighbouring ____ channels
Hair-like
tips
filaments
tip
potassium
How does basilar membrane vibration link to potassium influx?
In r____ state, there is a basal K+ i____ and n____ release.
Basilar membraner v____ induces b____ of s____ with increase K____ influx, increasing n____ release at the cell b____
In resting state (no sound) there is a basal K+ influx and neurotransmitter release.
Basilar membrane vibration induce bending of stereocilia which increase K+ influx, increasing neurotransmitter release at the cell base
What is meant by “Place code”?
F____ information is coded by the place along the c____ with the greatest m____ d____
Frequency information is coded by the place along the cochlea with the greatest mechanical displacement
What is meant by “Amplitude code”?
____ sounds produce ____ vibrations of the ____ membrane, making ____ ____ cells release more ____.
Louder
larger
basilar
inner hair
neurotransmitter
Hair cell neurotransmitter release activates b____ cells that form the a____ n____
Bipolar cells that form the auditory nerve (cranial nerve VIII).
Auditory pathways information…
. The auditory nerve enters the medulla, making s____ in a t____ manner
. Axons from the cochlear nuclei ascend to the s____ o____ c____ in the p____
. Inputs from each ear are processed by both o____ n____.
. A series of ascending projection along the midbrain ends up in the p____ a____ c____.
. Synapsis in a tonotopic manner
. Superior olivary complex in the pons
. Both olivary nuclei
. Primary auditory cortex
What is meant by transitory and conductive hearing loss?
T = O____ of the e____ c____, damage to the t____ m____
C = cause by problems in the o____
Obstruction of the ear canal (i.e. excessive ear wax), damage to the tympanic membrane.
Conductive hearing loss: caused by problems in the ossicles (i.e. otitis media during ear infections)
What are some different causes of permanent hearing loss
1. Otosclerosis = excessive g____ of o____, requires s____
2. S____ hearing loss = due to defects in c____ or a____ n____
3. Damage to h____ c____ caused by t____ or excessive exposure to n____
Otosclerosis: excessive growth of ossicles. Requires surgery.
Sensorineural hearing loss (most common defect), due to defects in cochlea or auditory nerve. Damage to hair cells caused by toxicity or excessive exposure to noise
How do cochlear implants work?
- Bypass d____ inner h____ cells
- Miniture flexible e____ array surgically inplanted in the cochlea through the o____ w____
- A receiver/s____ detects and processes sound into r____ signals, which are sent to the s____ (implanted inside the ____ during surgery)
- Miniture e____ positioned in frequency specific regions of the cochlea e____ electical signals, acitvating neighbouring b____ cells and the a____ nerve.
- degenerated, hair
- electrode, oval window.
- stimulator, radio, stimulator, skull
- electrodes, emit, bipolar, auditory
