Audiometric Interpretation Flashcards
The process by which sound travels to the inner ear and brain by way of the outer ear to middle ear
Air Conduction
To denote the difference in hearing sensitivity between bone conduction and air conduction thresholds
Air Bone Gap
The process by which sound travels to the inner ear and brain by way of the mastoid process, bypassing the outer and middle ear
Bone Conduction
Retrocochlear
Everything after the cochlea,that is, auditory nerve and brain
The 3 descriptors that characterize hearing loss
Type of HL - Conductive, Sensorineural and Mixed
Degree of HL- Mild, moderate, severe, profound
Configuration of HL- Flat, sloping, cookie-bite, rising, reverse slope, noise notch, etc
When sound is not transmitted efficiently through the ear canal, ear drum and ossicles of the middle ear
Conductive loss ( HL occurring in outer or middle ear)
What are some causes for a conductive hearing loss?
Middle ear infection
Perforated TM
Impacted Cerumen
Benign tumors
Absence or malformation of outer ear or ear canal or middle ear
(Conductive losses can often be medically or surgically treated)
Are bone conduction thresholds better or worse than AC thresholds?
Significantly better than AC thresholds and within normal range on the Audiogram when a CL is present
Characteristics of air bone gap
Always presents with better hearing by bone conduction than air conduction
ABG indicates a blockage or impairment to the conductive portion of the hearing mechanism
15dB or more at all frequencies
Occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain (retrocochlear)
Sensorineural HL
What can cause a Sensorineural HL?
Disease, Birth injury, drugs that are toxic to the auditory system, Genetic Syndromes, noise exposure, viruses, head trauma, aging, and tumors
Cannot be medically or surgically corrected and is a permanent loss
What are some characteristics of a Sensorineural HL on an Audiogram
When AC thresholds and BC thresholds are at the same (right on top of each other not he Audiogram)
When there is damage to the outer or middle ear and the inner ear or auditory nerves.
Mixed HL
What characteristics portray a Mixed HL on an Audiogram
A separation between the AC threshold and BC threshold in addition to abnormal BC thresholds (worse than 20dB on the Audiogram)
Refers to the severity of the HL
Degree of HL
Name 5 main degrees of HL
Normal, Mild, moderate, severe, and profound
The configuration or shape of the HL refers to
- the extent of HL at each frequency
- the overall picture of the hearing that is created (ex. A HL that only effects the HF’s)
A HL that generally varies within 10-15dB at all frequencies
Flat Loss
A HL that shows a gradual reduction from lower to higher frequencies
Gently Sloping
A HL showing a greater HL in the low frequencies and better hearing in the highs
Rising or Reverse Slope
A HL that shows Severe to Profound Loss in the low frequencies and no response in the mid or high frequencies
Corner Audiogram
A HL that shows better hearing in the low frequency range to a severe drop in the highs
Ski- Slope, HF or precipitous loss
indicates a HL due to noise exposure and is seen with a Noise induced notch which shows a sensorineural HL with a maximum loss typically between 3k and 6k Hz
Noise- Notch/V Notch
Degree of HL
0-20- Normal 21-40- Mild 41-70- Moderate 71-90- Severe 91+ -Profound
How to find the PTA - 3 Frequencies and 2 Frequencies
Add thresholds at 500, 1k and 2k and divide by 3
If the increase in loss between 500-1k and 2k is 15-20dB or more
Select the two frequencies that show the least loss, add those and divide by 2
In a sensorineural HL air conduction threshold are
The same as bone conduction threshold
An air-bone gap means the
Air conduction thresholds are worse than bone conduction threshold
A sensorineural component is the difference between
BC thresholds and the range of normal hearing
A pure conductive loss shows
All bone conduction thresholds within the normal limits
In a purely conductive loss
Sound is reduced before its arrival at the inner ear
A mixed loss exhibits
A sensorineural component and a conductive component
An Audiogram with les loss at the high and low frequencies than the middle frequency region is classified as a
Trough-shaped curve
Pure tone average estimates
SRT
