Hearing Flashcards
What are sound waves?
compression and decompression of the air (rarefaction) that reach your ears and allow to hear sounds
What is amplitude? How is it measured?
depth of the lowering and of the raising of the wave, measured in decibels (dB)
At which decibel levels are we feeling pain?
Above 130dB = pain
What level of decibel can cause hearing loss if heard for a prolonged period of time?
Above 85dB for prolonged time = hearing loss
What level of decibel causes immediate hearing loss?
Near sound above 120dB = immediate hearing loss
What is sensorineural hearing loss?
type of deafness caused by high-decibel sounds
What is frequency? How is it measured?
cycles per second that the wave has, measured in Hertz(Hz)
What is the range of frequencies that humans perceive?
Humans perceive sounds between 20 and 20,000 Hz (outside of this we don’t hear the sounds)
How is amplitude perceived?
Amplitude is perceived as the loudness of the sound
How is frequency perceived?
Frequency is perceived as the pitch of the sound
Are frequency and amplitude dependent?
No
What is the pinna? What does it do?
visible part of the ear (Collects sound from the environment and localizes them)
What is the auditory canal?
Conducts sounds energy from outer to middle ear
What are the parts of the middle ear?
Eardrum (tympanic membrane) and ossicles (3 bones)
What are the ossicles’ names?
- Malleus, incus, and stapes (amplify sounds coming from outside to transfer them to the cochlea)
- Stapes connects to inner ear at the oval window
What are the parts of the inner ear?
- Cochlea (contains receptors responsible for transducing energy from sound waves to electrical impulses)
- Semicircular canals (play a role in balance)
what are the 3 chambers of the cochlea?
- Scala timpani (Lower part)
- Scala media (middle part - organ of Corti)
- Scala vestibuli (upper part)
What does the cochlea coils around?
Coils around a bony pillar called the modiolus
What are the 2 types of fluids in the cochlea chambers?
- Endolymph (scala media)
* Perilymph (scala tympani and scala vestibuli)
How is called the membrane separating the organ of Corti from the scala tympani?
Basilar membrane
How is called the membrane separating the organ of Corti from the scala media?
Tectorial membrane
What are hair cells? Where are they located?
- Includes tectorial membrane
- Hair cells connect to ganglion cells, which carry info to the brain
- Outer hair cells closer to tectorial membrane and inner hair cells closer to basilar membrane
How is the basilar membrane differentially affected by the different wavelengths of sounds?
Because of its shape
• Thick at the base: high-frequency cannot move pat the beginning of the structure (peaks are observed early on)
• Low frequency waves are less affected by the thickness (tend to peak further down the apex)
What are mechanoreceptors?
activated when subjected to deformation (they are modified epithelium and not neurons)