Frye FONIX FP40D - Manual (Page 81)

Real-Ear Measurements 73
Chapter 5: Real-Ear Measurements
The Probe Option of the FONIX FP40 allows you to test hearing aids in the client’s ear, also known
as real-ear measurements. There are three real-ear measurement screens: Insertion Gain, SPL,
and Audibility Index. Each display presents different format from which to evaluate your hear-
ing aid fitting. There is also a Target 2-cc coupler screen that lets you take coupler measurements
and compare them to appropriate targets. The available test stimuli include pure-tone sweeps, the
Composite signal, the Digital Speech signals, and live speech (in spectrum analysis mode).
To take real-ear measurements, the FP40’s build-in sound chamber converts easily to a sound field
speaker. The larger microphone of the M200 dual microphone set, used as the measurement micro-
phone in coupler measurements, turns into a reference microphone for real-ear measurements. The
smaller microphone of the dual microphone set, used as a reference microphone when taking cou-
pler measurements, turns into the measurement microphone when taking real-ear measurements.
5.1 Preparation for Real-Ear Measurements
There are two steps to set up for a real-ear measurement. In the first step, you set the analyzer up
for testing. In the second step, you set the client up for testing with the analyzer. Once this is done,
you’re ready to take the real-ear measurements.
5.1.1 Setting up the analyzer for testing
To set the analyzer up for testing, you need to prepare the microphones and set up the sound field
speaker.
5.1.1.1 To set up the microphones and monitor headset
If not already in place, slide the Velcro mounting sleeves onto the reference and probe microphones.
See Figure 5.1.1.1.
Figure 5.1.1.1—Attaching the mounting sleeves