Audiometry Quiz 1

Why do you need a hearing test?

Who referred you for a hearing test?

-the factors that contributed to the referral

-the factors that could possibly contribute to the suspected pathology

-the test strategy that might be used

The outer ear

Evidence of craniofacial anomalies

-low set pinnae

-microtia/atresia

-lacerations, bleeding, bruising

-abnormal growths, patches

-signs of previous surgery

a

a

Ear canal

locate normal landmarks

check for the following conditions

-Atresia

-microtia

-collapsing canals

-excessive cerumen

-blood

-tm perforation

-tm color: is cone of light visible

Contraindications

excessive/impacted cerumen

drainage or inflammation of ear canal

bulging or red TM

perforation of TM

evidence of physical trauma

first hearing tests

two prongs referred to as tines

hilt stimulates bone conduction

When the external canal is occluded or if the middle ear is filled with fluid. The sound no longer escapes ad the sound appears louder by bone conduction.

Determines if a conductive loss is present

tuning fork held to pinna until quiet

fork is then held to mastoid bone

Negative Rinne: Patient can hear the tone, conductive loss

Positive Rinne: Patient cannot hear the tone, sensorineural loss

Fork is placed on forehead, tests between conductive and sensorineural hearing loss, which ear does the sound localize

Air conduction and Bone Conduction

pure tone thresholds of 20dB or less with air bone gap within 10dB

pure tone threshold of 15dB or less, air bone gap within 10dB

CONDUCTIVE: Thresholds by air

conduction are greater than 20dB, with

bone conduction thresholds within

normal hearing levels.

SENSORINEURAL: Thresholds by air

and bone conduction are greater than

20dB, and are within 10dB of each other.

MIXED: Thresholds by air and bone

conduction are greater than 20dB, with

bone conduction thresholds more than

10dB better than air conduction.

Hearing Loss can be described by its time of onset:

Congenital: present at birth

Acquired/Adventitious: occurs after birth

Acute: sudden onset, short duration
Chronic: of long duration
Sudden: having a rapid onset
Gradual: occurring in small degrees
Temporary: of limited duration
Permanent: irreversible
Progressive: advancing in degree
Fluctuating: aperiodic change in degree

Unilateral: pertaining to one ear only

Bilateral: pertaining to both ears

DESKTOP and PORTABLE. Desktops are found in standard audiology clinics and cannot be moved. Portables are smaller units that can be transported.

Both are called discrete frequency audiometers since we can test individual frequencies from 125Hz to 8000Hz. In some cases, audiometers can go up to 12,000Hz.

for regulating pure tone and
speech loudness

-10dB to 120dB

-10dB to 100dB

5dB increments

125Hz to 8000Hz.

Portables generally have a single channel
Desktops have two channels
Single Channel: Only one signal can be presented at a time.
Dual Channel: One signal can be presented from one channel, and another signal can be presented from the other, simultaneously.

INSERT EARPHONES

SUPRA-AURAL EARPHONES

BONE OSCILLATORS

Loudspeakers are used when testing in the sound suite without earphones or insert phones.

Typically used in pediatric behavioral testing, or testing with hearing aids

Hearing testing must be done is a special
environment, i.e. in a sound proof or sound
attenuated booth. It is also called a test
suite. This booth must meet standards for
acceptable noise levels present in the booth.
The walls are 4” thick and are lined with sound
treated materials that absorb sound and reduce
reflections. Booths can be single or double
walled.

Sound booths can be one-room or two-room suites.

For single room booths, the tester is outside the sound treated environment (all must be quiet).

For double room booths, the patient is in one sound treated room, and the tester and test equipment are in an adjacent sound treated room (preferred).

In both cases, there is a window through which the patient and tester can see each other.

The patient is seated in a chair inside one of the sound treated rooms at a 45 or 90 degree angle from the tester.

This keeps the patient from seeing the tester.

If testing with speakers, the patient is placed equi-distant at a 45 degree angle from each speaker.

In addition to an adequate test environment, the test
equipment must be functioning properly to assure
accurate results. An annual process known as
calibration is done on all audiometers, tympanometers
and all other test equipment to make sure that the
signal being produced is actually the one expected.
There are standards regarding these values so that
there is consistency from one audiometer to another
and one test site to another. The standards were
developed by the American National Standards
Institute (ANSI).