Chapter 1 1
An Overview of the FP35
Welcome to the FONIX FP35 analyzer! The FONIX FP35 provides quick, accu-
rate information about how well a hearing aid works. It uses a graphical display
or numerical table to show how much amplification the aid provides, which fre-
quencies it amplifies, and how much distortion is creates.
The FP35 hearing aid analyzer is a lightweight instrument notable for its ease
of use. It has an intuitive interface to lead novice users through the process
of hearing aid prescription and real-ear testing, but the interface is versatile
enough for experts to use without feeling hindered.
You can reach the menus from any screen. To make finding what you are look-
ing for quick and easy, and to avoid confusion, the pop-up menu screens dis-
play only the choices relevant to the application currently in use. The FP35 also
offers pop-up help windows that guide you through the possible steps available
from the current screen.
The FP35 uses a backlit LCD with an adjustable contrast for its main display,
and it has a thermal printer built in so that you can print hard copies of gath-
ered data no matter where you are. The FP35 also has an external monitor
option that allows the simultaneous display of the built-in LCD and an external
monitor. Most computer monitors will work with this feature, although the FP35
display is only in two colors. There is also a parallel port on the back of all
FP35 analyzers, allowing the use of an external printer.
The FP35 features three different pure-tone tests. The normal sweep covers a
detailed range of frequencies; the fast sweep offers a continuous signal, updat-
ing as fast as once every three seconds; the short sweep is a quick test (under
two seconds) covering standard audiometric frequencies. You can view the
curves in either gain or sound pressure level.
Indications for use
The FONIX FP35 Hearing Aid Analyzer allows the user to test the characteris-
tics of a hearing aid using coupler and optional real-ear measurements. These
characteristics include: Frequency response, harmonic distortion, equivalent
input noise, and compression. Coupler measurements are performed inside
a sound chamber. Real-ear measurements are performed with a small probe
microphone inside the patient’s ear. This manual provides detailed instructions
on the measurement capabilities and user interface of the FONIX FP35.
