Test 2 Flashcards
What are the conductive portions of the ear?
outer and middle ear
What is the sensory portion of the ear?
inner ear
What are the 5 steps of an AC threshold search?
- tone presented 10 dB below where the patient responded during familiarization.
- The level of the tone is raised in 5 dB steps until the patient responds.
- the tone is then decreased by 10 dB and presented again
- The level of the tone is then raised 5 dB until the patient responds
- steps 2 & 3 are repeated until patient responds at the same frequency 50% of the time.
What are the frequencies an AC threshold search should be made at?
- initial test frequency should be 1000 Hz.
- follow in order, 2000, 3000, 4000, 6000, and 8000
- retest 1000 Hz
- test 500, 250, and 125 Hz
What are the procedures for BC testing?
- procedures are basically the same as AC thresholds.
- frequencies: 1000, 2000, 4000, retest at 1000, 500 and 250 Hz
- Can start in either ear (vibration of the skull will result in about equal stimulation of both cochleas)
What are the thresholds for Normal Hearing?
- 0-25 dB HL
- With children hearing loss greater than 15 dB may interfere with speech and language acquisition
- usually no noticeable impairment in adults.
What are the thresholds for Mild Hearing Loss?
- 26-40 dB HL
- Simulate the experience by closing off the tragus
- Can miss 25% to 40% of speech signal
What are the thresholds for Moderate hearing loss?
- 41-70 dB HL
- Can miss up to 80% of average level conversational speech (50 db HL)
- impact on speech and language development
- Impact on social/emotional growth
- Impact on adults; social interaction, depression
What are the thresholds for severe hearing loss?
- 71-90 dB HL
- Miss about 100% of average conversational speech
- Timely intervention critical
What are the thresholds for Profound hearing loss?
- greater than 91 dB HL
- Can miss 100% of all speech
- Early intervention for child is a MUST
- accessibility to sound with and without devices (hearing aids, CI or both)
What are the 6 different audiogram configurations of the various hearing loss types?
flat, rising, sloping, precipitous, 4000 Hz Notch, corner audiogram
Define conductive hearing loss
occurs when sound waves do not reach the inner ear
Define Sensorineural hearing loss
- occurs when sound waves are not processed correctly
- damage occurring in the inner ear
Audiogram results are interpreted in terms of what?
- amount of hearing by air conduction (tests the entire auditory pathway)
- Amount of hearing by bone conduction (tests the inner ear and auditory nerve only)
- Relationship between air and bone conduction. (difference between the AC and BC results implies a problem with the conductive system, known as an air-bone gap)
- AC-BC = ABG
What should you look for on a sensorineural hearing loss audiogram?
- hearing loss in both AC and BC thresholds
- No ABG = Thresholds of AC and BC thresholds are within 10 dB of each other
What should you look for on a conductive hearing loss audiogram?
- Normal BC thresholds
- hearing loss in AC thresholds
- ABG = Difference between BC and AC thresholds is greater than 10 dB
What should you look for on a mixed hearing loss audiogram?
- BC and AC thresholds show a hearing loss
- ABG = difference between BC and AC thresholds is greater than 10 dB
What is Pure Tone Average (PTA)?
The average threshold levels for each ear at 500, 1000, and 2000 Hz (add and divide!)
What is mixed hearing loss?
a combination of conductive and sensorineural hearing loss, occurring simultaneously in the same ear. Air conduction results will be poorer than bone conduction results
What is a threshold and how do you find it?
In audiometry, the level at which a stimulus, such as a pure tone, which is barely perceptible. Usually clinical criteria demand that the level be just high enough for the subject to be aware of the sound at lear 50% of the time it is presented.
What is the air unmasked symbol for the right and left?
right = O left = X
What is the air masked symbol for the right and left ears?
Right = Triangle Left = Square
What is the bone unmasked symbol for the right and left ear?
right =
What is the bone masked symbol for the right and left ear?
right = [ left = ]
What is the sound field symbol for the right and left ear?
Right = S Left = S
What is the Aided symbol for the right and left ear?
right = A left = A
What is cross hearing?
The reception of a sound signal during a hearing test at the ear opposite the ear being tested
- it is possible for the stimulus to travel from the poorer ear to the better ear
- can occur when testing by air conduction, bone conduction and speech testing
Define interaural attenuation (IA)
as sound travels from one side of the head to the other, a certain amount of energy is lost in transmission. This varies with frequency (Hz) and individual patients
What is the IA for air conduction when using supra aural headphones or insert headphones?
supra aural headphones = 40 dB
insert headphones = 60 dB
What is the IA for bone conduction?
0 dB
Define Masking
The presentation of sound to the contest ear that prevents the patients form hearing the test sound in that ear
Define TE
Test Ear (the ear currently being tested)
Define NTE
Non-Test Ear (the ear not currently being tested)
What are some benefits of using insert earphones?
They help block out sound better and are often more comfortable to wear for the patient
