BIO T5 Flashcards
What is the measurement unit for loud sounds?
decibels (dB)
Frequency is measured in X and describes….
the rate at which sound waves oscillateX= hertz (Hz)
Part of the outer ear are the:
- the pinna
- auditory canal
Part of the middle ear are the
- ossicles
- tympanic membrane
Part of the inner ear are
- oval window
- cochlea
- auditory vestibular nerve
What is the importance of hair cell depolarization in auditory perception?
crucial for the transduction of mechanical stimuli (sound waves) into electrical signals that can be interpreted by the brain, enabling us to hear and perceive sound.
What is the specific neurotransmitter released by hair cells in the cochlea to stimulate sensory neurons?
Glutamate
How are the calcium and potassium channels in the hair cells connected?
The intracellular release of calcium during depolarisation also controls the potassium channels
What is the auditory range of humans?
0-200db/20-20.000Hz
20-50db for Normal Speech
What is the abbreviated pathway of sound to the ear?
Sound waves gathered into the outer ear are transduced from air pressure into mechanicalenergy in the middle-ear ossicles (the hammer,anvil, and stirrup) and into electrochemicalactivity in the inner-ear cochlea.
McGurk effect
brains give more credit to visual information than to auditory input
THE SOUND AND THE EAR ?
- Sound waves gathered into the outer ear aretransduced from air pressure into mechanicalenergy in the middle-ear ossicles (the hammer,anvil, and stirrup) and into electrochemicalactivity in the inner-ear cochlea.
Why doesn’t unilateral damage to the inferior colliculus ormedial geniculate nucleus lead to deafness in one ear?
sound is split
What is the role of the basilar membrane in sound detection?
The basilar membrane senses different sound frequencies at specific locations.
* Low-frequency sounds: The membrane vibrates in synchrony with the sound waves.
* The number of firing cells identifies loudness
What happens in theTonotopic maps on the basilar membrane and cochlear nucleus?
From the base to the apex of the cochlea, the basilar membrane resonates with increasingly lower frequencies. This tonotopy is preserved in the auditory nerve and cochlear nucleus.
Why does sound localisation vary?
Across three domains:
* Difference in time of arrival
* Difference in intensity between the ears (sound shadow)
* Phase difference between the ears
How common are hearing disorders?
Hearing loss is the third most common condition among older adults
* 25-40% of people over 65 years old
* 50% of people over 75
* 80% of people over 85
What leads to conductive hearing loss
Diseases, infections, or tumorous bone growth can prevent the middle ear from transmitting sound waves properly to the cochlea. It includes all pathologies in the external and middle ear.
What leads to sensorineural hearing loss
Nerve deafness: damage to the cochlea, the hair cells, or the auditory nerve (disease, exposure to loud noises)
Presbycusis
Age-Related Hearing Loss
Age-Related Hearing Loss
Degeneration of the sensory cells in the cochlea, supportingcells and auditory nerve; brain areas responsible for languagecomprehension become less active, decreased attentionalcapacities
Cochlear implant
medical device that uses electricity tostimulate the spiral ganglion cells of the auditory nerve torestore sensorineural hearing loss<img></img>
LANGUAGE PERCEPTION
Listening to speech activates extensive areas in the temporal lobe, with the activation strongly biased toward the left hemisphere
* Early organization of auditory areas and lateralization for language similar to adults.
Developmental changes in native language phonetic perception?
Significant increase in performance for the native-language contrast in the first year
* Decline in nonnative perception over the same time period
* <img></img>
Transduction by hair cell
Depolarization of a hair cell
THE AUDITORY PATHWAY
How does sound localisation vary?
What leads to central auditory processing disorders
What can be said about brain activity in musicians and non-musicians?
Nonmusicians showed larger activity on the right than the left hemisphere, whereas musicians showed symmetrical activation
How can we hear sound?
