4: Real-Ear Measurements
27
Only the larger reference microphone is used during the leveling process. However,
to speed things up and ensure the client is in the same position during leveling and
during the measurement process, it is recommended that you insert the probe tube
in the client’s ear for the leveling process. See Section 4.2.4 for more details.
To level:
1. Place the earhook on the client’s ear.
2. Position the reference microphone on the earhook’s wedge above the client’s ear.
See Figure 4.2.4B.
3. Insert the probe tube into the client’s ear, if desired. (The probe microphone is
not used during the leveling process.)
4. Position the sound field speaker 12–15 inches from the client’s head, at a 0º
or 45º azimuth. (We recommend 45º azimuth in order to produce the most
repeatable results.)
5. Select the azimuth used in the SOUND FIELD setting in the real-ear menu. See
Section 4.2.5 for details.
6. Press [F5]—LEVEL in any of the real-ear measurement screens (not the
audiogram entry screen).
7. Press [START/STOP]. The instrument will now attempt to level the sound field
speaker.
These are the possible leveling status:
• LEVELED 0º or LEVELED 45º—The leveling process was correct within 2 dB.
The azimuth used is indicated.
• UNLEVELED—The leveling process was incorrect at least 6 dB. You should
check the speaker, client, and reference microphone position and try to level
the instrument again. No azimuth is indicated for this status.
• 0º or 45º—A status showing only the azimuth indicates that the leveling
process was correct somewhere between 2 dB and 6 dB. Just as with the
UNLEVELED status, you should check the speaker, client, and reference
microphone position and try to level the instrument again. However, if
repeated attempts fail to reach a leveled status, you can consider this stage
“good enough.” Be aware that measurements when the instrument is in the in-
between stage will not be as accurate as measurements taken when the sound
field is leveled.
Note: The environment should be quiet during leveling. Noise can affect the leveling
results, though the FP35 does use measurement methods to minimize the impact of
external noise.