Clinical Application Of The Ac440 Tests; Air Conduction Audiometry - Interacoustics Affinity 2.0 Additional Information

2.0
Affinity Additional Information

1.7 Clinical Application of the AC440 Tests

This section will give a short introduction to the clinical applications of the AC440 module. The methods
described here primarily based on the textbooks by Stach (1998) and Katz (2002) and describes one way of
performing the individual tests. Other standards may, however, dictate other procedures.

Air Conduction Audiometry

In air conduction audiometry, a test signal is presented to the test subject via headphones or insert phones.
The test subject responds to the signal by pressing a patient response button. The audiometric threshold is
defined as the lowest intensity at which the patient is able to detect the test signal 50% of the time
The purpose of air-conduction audiometry is to establish the hearing sensitivity at various frequencies. The
test provides information about the conductive and sensory systems of hearing but cannot distinguish
between conductive and sensorineural hearing losses.
Required Items:
•
2.0
The Affinity hardware
•
Licensed AC440 Audiometry module within your Affinity
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Headphones or insert phones
•
A response button
Test Procedure:
1) Open the Affinity Suite through your patient management system, Noah or OtoAccess™.
2) Ensure you are in the AUD module of the Suite and if needed select a test protocol in the List of
Protocols.
3) Perform otoscopy to make sure that any anatomical abnormalities are taken into account and that
cerumen is not obstructing the ear canal. Perform a medical history to find out whether there are any
confounding factors which may prevent you from performing the test or make considerations for. It is
also good to ask if the patient is experiencing tinnitus. If yes, you may consider doing the test using
warble tones or narrow band noise instead of pure tones which can be hard to distinguish from the
tinnitus at some frequencies.
4) Select the input and output for channel 1.
If masking is needed, use the channel 2 to determine masking level and frequency. Note that this
decision is usually made after performing an unmasked audiogram based on differences in thresholds.
Channel 2 should be muted or switched off in the beginning of the evaluation. If preferred, Auto
Masking or Masking Help can be turned on.
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hardware
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