Mod 4: Pure Tone Audiometry

Threshold

softest sound a person can hear 50% of the time.

Audiometers

pieces of equipment that are used to obtain hearing threshold

Audiologist generally do not use tuning forks test

True

Calibration

documented comparison of a measurement device against a traceable reference device.

Air conduction testing measures the overall

degree of hearing loss (normal, mild, moderate)

Air conduction cannot determine _____

specific type of hearing loss

What frequences does routine test include in air conduction

250 hz through 8,000 hz

250, 500, 1000, 2000, 4000, 8000

When might 3,000 and 6,000 hz be tested in air conduction

if noise exposure is a risk

What frequences does routine test include in bone conduction

500 hz to 4000 hz

500, 1000, 2000, 4000 Hz

which conductions uses headphones, insert earphones, or speakers

air conduction

Air conduction or Bone conduction?
Ear is being stimulated by sound waves traveling through the air

Air conduction

Air conduction or Bone conduction?
Sound must travel through the entire auditory system to elicit a response

Air conduction

Insert earphones are preferred for

comfort, better infection control, less need for masking, and avoidance of ear canal collapse

PTA

Pure Tone Average

Which frequences uses the average of 500, 1000, and 2,000 hz

three freq PTA

which frequency uses the average of the best (lowest value) and two threshold at 500, 1,000 and 2000 hz

two freq PTA

Which freq is often a better predictor of the threshold for speech especially with steeply sloping audiometric configurations

Two freq PTA

Variable PTA

Average of the poorest three thresholds at 500, 1000, 2000 and 4000 Hz

Variable PTA is often more effective than the

traditional three-frequency PTA in estimating the degree of communication impact

What is reliability of test results based on

Calibration of equipment

Test environment

Examiner’s expertise

Patient performance

False negative responses

When a patient fails to indicate they heard a tone

Misunderstood, forgotten, fell asleep

Deliberate false negatives

False Positive Response

When a patient responds when no tone has been presented

Highly motived to respond and do well, patients with tinnitus

In children, misunderstanding

patient should never be able to see the tester push the buttons

True

Bone conduction uses

bone conduction vibrator and is also placed on the forehead or behind the ear

bone conduction

High intensity sounds produce a vibro-tactile response.

Electroacoustic calibration is recommended

annually

•Why is it important that audiological equipment be calibrated annually?

to guarantee accurate sound outputs, ensure consistent diagnostic results, and maintain compliance with national and industry standards

What is cross- hearing?

sound crosses the skull and is heard by the opposite ear.

What is interaural attenuation?

how much the sound decreases before reaching the opposite ear.

Masking

introducing a noise signal to the non-test ear during an hearing evaluation to ensure that the opposite ear does not falsely detect the sound

keeps the opposite ear from “helping.”

why is masking important?

prevents the non-test ear from hearing the sound, ensuring you get an accurate result for the ear being tested.