The Ear Flashcards
What is a hearing aid
A small electronic device that you wear in or behind your ear
What does a hearing aid do
- it makes some sounds louder
- can help people in quiet and noisy situations
What are the 3 basic parts of a hearing aid
- a microphone: receives sounds thorough the mic. It converts sounds waves to electrical signals and sends to the amp
- an amplifier: increases the power of signals and sends them to the ear through a speaker
- a speaker:
What do analog hearing aids do
Convert sound waves into electrical signals, which are amplified
What do digital hearing aids do
Convert sound waves into numerical codes, similar to the binary codes of a computer, before amplifying them
What is a hearing loop
A special type of sound system for use by people with hearing aids
What does a hearing loop system provide
A magnetic, wireless signal that is picked up by the hearing aid
Why have a hearing loop system
- cuts out unwanted background noise
- no need to use a receiver/headset
- sound goes directly into the hearing aid
- can be used by anyone with a compatible hearing aid
- it is inconspicuous
- cost effective
- any number of users can use the system
What are the 5 types of hearing aid
- behind the ear
- mini behind the ear
- in the ear
- in the canal
- completely in canal
What are the 3 parts that the ear are separated in to
- Outer
- Middle
- Inner
What is the inside of an ear
The middle ear is an air-filled cavity that contains the eardrum and three small bones that help transmit sound to the inner ear
How is the middle ear connected to the throat
Via the auditory tube
The pinnae
Sound waves pass through the air are channelled into the ear by the outside parts of our ears - the pinnae
The eardrum
The waves pass down the external ear passage and cause the eardrum at the end to vibrate
The middle ear
The eardrum is allowed to vibrate because as the drum separates another air filled chamber - the middle ear - from the external ear
The eustachian tube
A small passageway - the eustachian tube - connects the middle ear to the throat and allows the middle ear to be at the same pressure as atmospheric air
What are the bodies 3 smallest bones
- Malleus
- Incus
- Stapes
The malleus, incus and stapes + oval window
Transmit vibrations of the eardrum across the middle ear before striking a further membrane - the oval window. This magnifies the intensity of the vibrations
The cochlea (on the other side of the oval window is the inner ear and the cochlea)
The cochlea contains a jelly-like fluid, the perilymph, contained in a coiled tube spiralled like a snails shell.
The perilymph + the organ of corti
Membranes lines with sensitive hair-like structures called the organ of corti are located within the perilymph
The round window
A drum-like membrane - the round window - allows vibrations from the oval window to pass through the fluid, rippling the membranes and stimulating the sensitive hairs
The sensitive hairs
These fire impulses to the brain along the auditory nerve and are registered by the brain as sounds
What are connected to the cochlea but are not involved in hearing
Fluid filled tubes (semi-circular canals) and swellings (ampullae)
Semi-circular canals + ampullae
In these tubes, movement of the fluid results in messages being sent to the brain that give us information on orientation and movement
Otoliths
Microscopic granules called otoliths press against the sensitive hairs if we alter our position or rate of movement. This is vital in helping us maintain balance both when stationary and when moving
Some people are born without hearing but most cases of deafness are the result of what
Illness
-eg meningitis or an injury to the head, repeated exposure to loud noises or simply growing older
What is hearing loss the result of
Sound signals not reaching the brain along the auditory nerve
Conductive hearing loss
When sounds are unable to pass from the outer ear to the inner ear are usually because of a blockage (such as are wax or build up from an ear infection
These can become fused and so cannot pass the sound across the middle ear
Sensorineural hearing loss
Caused by damage to the sensitive hair cells of the organ of corti in the inner ear or damage to the auditory nerve
What is the definition of deafness
The conclusion of lacking the power of hearing or having impaired hearing
How many babies are born deaf
3 in 1000
Why are babies born deaf
Due to genetics or my MMR, meningitis, stroke
What are the treatments for deafness
- removing wax blockage
- surgical procedures
- hearing aids
- cochlear implants
What is loudness measured in
Decibels (dB)
What is pitch frequency measured in
Hertz (hz)
What are parts of the external ear
- pinnae
- eardrum
What are parts of the middle ear
- eustachian tube
- malleus, incus, stapes
- oval window
What are parts of the inner ear
- cochlea
- perilymph
- organ of corti
- round window
- auditory nerve
