MA 25 Operating Manual
10
4.
Performing tone audiometric tests
Hearing threshold levels can be determined by presenting test signals to the test subject with the included
earphones (air conduction – AC). The purpose of AC audiometry is to establish the hearing sensitivity at various
frequencies. The test can specify the AC loss but cannot distinguish between abnormality in the conductive
mechanism and sensorineural mechanism.
The patient should sit at a distance of at least 1 m from the device.
Eliminate any obstructions which will interfere with the placement of the earphone cushions on the ear (i.e. hair,
eyeglasses).
Ensure that the headphones are positioned correctly: Red side on the right ear, blue side on the left ear. Adjust the
headband of the headphones so that the earphones are positioned at the correct height (i.e. the sound output grid
exactly facing the ear canal).
Prior to hearing threshold level measurements, the following instructions should be given. "You will now hear a
variety of pitches with various loudness levels. Please push the response switch when you hear a tone and release
the button when you no longer hear it. If not using the response switch, ask the patient to “raise their left or right
hand when you hear the tone in the left or right ear".
