Audiology Flashcards
What are the components of sound?
Frequency- HZ (pitch)- cycles per second
Duration (time)
Amplitude- dB (loudness)
What are the three advantages of transformer action?
- area advantage
- curved membrane buckling
- lever action advantage
What is impedence mismatch?
Without transformer action the sound going from air (external ear) to fluid (inner ear) would dampen and, thus, sounds would not be heard as easily. We lose 30dB going from air to fluid.
What is transformer action?
Sound waves into the ear and vibrate the temp in the membrane, which vibrates the ossicle chain. The stapes then presses into the oval window at a high rate of vibration sending the waves with the fluid, into the auditory nerve and then to the brain.
What is area advantage? I
The size of the tympanic membrane is 17 to 18 times larger than the oval window
What is curves membrane buckling?
The tympanic membrane is curved to take in more sound waves
What is lever action advantage?
The way in which the ossicle chain functions
Degrees of hearing loss
Normal- 0-20
Mild- 25-40
Moderate- 45-65
Severe- 70-85
Profound- 90-110+
What Dr. Tice’s 5 rules for hearing?
- if ACT and BCT are WNL and do not dinner more than 10dB= normal
- if ACT and BCT are WNL and they differ more than 10dB= conductive dysfunction
- if ACT is not WNL and BCT is WNL, and they differ more than 10dB= conductive hearing loss
- if ACT and BCT are not WNL and they do not differ more than 10dB= sensorineural hearing loss
- if ACT and BCT are not WNL and BCT is better by 10dB= mixed hearing loss
What is the ossicle chain?
Malleus
Incus
Stapes
What is meniers disease
Vertigo and its senseurineural
Tinnitus
Usually just affects one ear
Ages 20-50
What is otosclerosis
Bone growth in the middle ear
Conductive hearing loss
Carhart’s notch at 2000k. BCT dips down
What is noise induced hearing loss?
Prolonged exposure to loud sound results in damage to hair cells of the inner ear
Sensorineural hearing loss
Both BCT and ACT drop at 4000
Middle ear infection
Infection of the the middle ear
Conductive