Term
| What are the two types of deafness? |
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Definition
| conductive and sensorineural |
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Term
| What causes conductive deafness? |
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Definition
| disease in the middle ear interfering with the transmission of sound to the cochlea |
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Term
| What causes sensioneural deafness? |
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Definition
| injury or degeneration of the nerve elements on the cochlea or auditory nerve |
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Term
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Definition
| if the base of the tuning fork is held firmly to a subjects skull the sound can reach the cochlea independently of the middle ear |
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Term
| What is conductive deafness? |
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Definition
| subject will be deaf to ordinary air conduction but will show no deafness to bone conduction |
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Term
| What is sensioneural deafness? |
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Definition
| the subject will be deaf to both air and bone conduction |
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Term
| Describe the Rinne's test |
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Definition
1. strike a tuning fork and hold it by the subjects ear until they can no longer hear it, then immediately place it against their mastoid process. Can sound be heard again?
2. Block off ear and repeat.
3. Repeat for other ear. |
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Term
| What are the results of Rinne's test? |
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Definition
1. in normal hearing, once the sound wave has dissipated enough to be lost via air conduction, there is not enough to be detected by bone conduction
2. if conductive deafness is simulated, the tuning fork can be heard through bone conduction as the air conduction threshold is higher, but bone conduction remains the same |
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Term
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Definition
1. strike a tuning fork and hold the base firmly against the subjects forehead in the midline
2. Is sound louder or the same in each ear?
3. repeat blocking off one ear
test bone conduction in normal and impaired ear |
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Term
| What are the results of Weber's test? |
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Definition
If the sound lateralizes (is louder on one side than the other), it suggests the following:
1. an ipsilateral conductive hearing loss
2. a contralateral sensorineural hearing loss (2)
blocked ear hears the sound louder because ambient noise (air conduction) masks bone conducted sound in unblocked ear |
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Term
| Describe the conduction thresholds if you have conductive deafness |
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Definition
increased threshold through air conduction
normal threshold through bone conduction |
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Term
| Describe the conduction thresholds if you have sensioneural deafness |
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Definition
| increased threshold for both air and neural conduction |
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Term
| If a subject has moderate, bilateral sensorineural hearing loss, what are the effects of the Rinne's test? |
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Definition
| if the middle ear is intact then air conduction > bone conduction, so will not re-hear sound on mastoid process (as if normal) |
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Term
| If a subject has moderate, bilateral sensorineural hearing loss, what are the effects of the Weber's test? |
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Definition
| Equal hearing loss in both ears, so sound heard equally in both ears (as if normal hearing) |
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Term
| If a subject has moderate, bilateral sensorineural hearing loss, what are the effects of a pure tone audiometry test? |
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Definition
thresholds are elevated
40-60dB hearing level |
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Term
| What does an audiometer test? |
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Definition
| receptors across frequency range (across entire cochlea/basilar membrane) |
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Term
| What is the range of hearing of the human ear? |
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Definition
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Term
| Which frequencies do you lose with age? |
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Definition
| lower but predominately higher |
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Term
| What is meant by the term threshold? |
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Definition
| the lowest intensity which can be detected for a particular frequency |
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Term
| What can audiometry diagnose? |
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Definition
conductive hearing loss
if the conductive threshold are elevates above the bone conduction thresholds then a subject has conductive hearing loss |
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Term
| What can cause conductive hearing loss? |
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Definition
- physical damage to outer/middle ear
- infection/fluid in middle ear
- otosclerosis
- damage to tympanic membrane |
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Term
| What can cause sensioneural hearing loss? |
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Definition
- damage to inner ear
- loss/damage of hair cells
- brianstem/nerve damage
- peripheral damage
- central damage |
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Term
| Using inter neural intensity difference, which frequencies are easier to detect? |
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Definition
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