Audiogram Flashcards
Define Audiometric Threshold
The lowest intensity at which the listener can identify the presence of a signal at least 50% of the time.
How is Audiometric Threshold determined?
The tone is presented at a clearly audible level. A level of 40 dB is used for those with no apparent hearing loss and a level of 70 dB is used for those who have obvious difficulty.
If no response is obtained the level is increased by 20 dB
Once the patient responds, the intensity is lowered by 10 dB increments until there is no response.
When the patients fails to respond the intensity level is raise in 5 dB increments until a response is obtained. until the patient responds.
. Then the level is lowered in 10 dB steps, then repeat.
According to the American National Standards Institute (ANSI) S3.21, threshold is determined as “the lowest hearing level at which responses occur in at least one-half of a series of ascending trials, with a minimum of two responses out of three required at a single level.”
How is Pure Tone Average determined?
The average of 500 Hz, 1000 Hz,
2000 Hz, and 4000 Hz
Results of 500 Hz+1000 Hz+2000 Hz+4000 Hz divided by 4
Result is the Average.
Explain Bone Conduction
There are three Mechanisms underlying bone conduction hearing:
The inertial response of the middle ear ossicles and the inner ear fluids.
The distortional response of the cochlear bony labyrinth.
Radiation of sound energy into external ear canal.
Define Inter-aural Attenuation
Interaural attenuation refers to the reduction in sound when it crosses from one ear to the other. This crossover phenomenon occurs principally through bone conduction.
Determining Inter-Aural Attenuation
Circumaural Earphones Air Conduction Supra-aural Earphones Minimum to cross over is 40 dB Air Conduction Insert Earphones Minimum to cross over is 65 dB Collapsing ear canals Bone Conduction There is no minimum Crosses over at all intensities
What is the name of the Audiometric test?
Carhart-Jerger Modified Hughson-Westlake Procedure For Finding Threshold
What is a Spondaic Word?
Two syllable word spoken with equal stress on each syllable. Measures SRT.
What is a Phonetically Balanced Word List?
one syllable common words
50 is recommended
no familiarization is needed
What is Word Recognition testing?
It determines the extent of the speech-recognition difficulty
Aids in diagnosis of the site of the disorder in the auditory system
Helps the clinican make a prognosis for the outcome of treatment efforts
Usually tested with spondaic words.
How do you conduct a reliability check?
1000 Hz two times
