Week 2 Sound and Hearing Flashcards
How is sound produced?
* When matter vibrates (moves)
* As an object vibrates, it gives energy to the particles of matter around it
* The energy moves with a series of compressions and rarefactions
* This means sound is produced as a longitudinal wave
What is AMPLITUDE?
Describes the energy in the wave = Loudness is related to the amount of energy carried by a wave
What is AMPLITUDE?
Describes the energy in the wave = Loudness is related to the amount of energy carried by a wave
What is PITCH?
A measure of how high or low a sound is
What are voice sounds known as?
• Harmonics - they come from vibrations of the vocal folds
What is a spectrogram?
A spectrogram is a visual representation of the spectrum of frequencies as it varies over time.
What is a formant?
The ability to manipulate or change the shape of your sound waves to change the effect of your voice (eg changing pitch)
Label the components of the outer ear (auricle - to capture sounds)
What is the external acoustic meatus? Where is it?
Connects auricle to tympanic membrane
Passageway for sound waves to travel to be directed to middle → inner ear.
• through temporal bone
• slightly S-shaped
➢Lateral third
➢Cartilaginous
➢Ceruminous and Sebaceous Glands
➢ Produce cerumen – ‘ear wax’
➢Medial two thirds
➢Bony
➢Lined with skin continuous with tympanic membrane
What is the anatomical name for the ear drum? Where is it located?
Tympanic membrane?
How do we hear?
- Soundwaves enter the ear
- They hit the tympanic membrane and it starts to vibrate.
- The vibrations then move onto three tiny bones in the middle part of the ear called ossicles - the three bones are Malleus, Incus and Stapes (MIS)
- The stapes is attached to the oval window - the vibrations here set the fluid in the inner ear into motion
- The fluid runs through three main chambers in the cochlear, separated by sensitive membranes.
- The basilar membrane is the important one for hearing. It encases the middle fluid filled chamber (scala media) and reads all sounds and communicates the info to the nervous system via the organ of corti
- The basilar membrane is covered in fibres that move with pressure (different frequency sounds are felt in different parts)
- The movement of the fibres interacts with the hair cells in the organ of corti, which in turn triggers an electrical impulse to travel from the organ of corti along the cochlea nerve to the cerebral cortex - this is what we interpret as sound
What are the components of the middle ear? (MIS)
* Mucous membrane lined, air filled space
* Contains ossicles (MIS) and associated muscles
- Malleus (muscle - tensor tympanis)
- Incus
- Stapes (muscle - stapedius)
* Ossicles communicate with the inner ear (via the stapes) and the pharynx via pharyngotympanic tube
What is the common name for the pharyngotympanic tube
eustachion tube
How does the middle ear connect to the inner ear
Through the oval window (via the oval shaped part of the stapes)
What is the function of the Pharyngotympanic or eustachian tube
* Connects tympanic cavity to nasopharynx
➢Drains middle ear cavity- keeps it aerated
* Equalise pressure in the middle ear
➢This allows free movement of TM
* Tube normally closed
➢must be actively opened
* first 1/3rd is bone – rest cartilage
➢relevance to development
What are the components of the middle ear?
- Hearing apparatus- containing the receptor HAIR CELLS and Cranial Nerve for Hearing (CN VIII)
- Vestibulocochlear Organ - for balance and hearing
- Cochlear
- Cochlear Organ (within the cochlear)
Define the two types of hearing impairments
- Conduction deafness – something hampers sound conduction to the fluids of the inner ear (e.g., impacted earwax, perforated eardrum, osteosclerosis of the ossicles)
- Sensorineural deafness – results from damage to the neural structures at any point from the cochlear hair cells to the auditory cortical cells
What is Tinnitus?
ringing or clicking sound in the ears in the absence of auditory stimuli – is disorder of the cochlear
What is Meniere’s syndrome?
entire labyrinth disorder (affects the cochlea and the semicircular canals) causing vertigo, nausea, and vomiting
Common name for malleus
hammer
Common name for malleus
hammer
Common name for incus
anvil
common name for stapes
stirrup
