This FONIX 8000 Hearing Aid Test System is designed to test hearing aids. There
are two major types of hearing aid tests: coupler and real-ear.
Coupler measurements are performed in a sound chamber using a coupler or artificial ear that directs the sound to a measurement microphone. The measurement microphone thus listens to the sound coming from the hearing aid. The sound chamber is constructed so that external sounds are attenuated and so that there is a place
within the box that contains a reference point where the sound is calibrated in both
amplitude and frequency. Tests can be performed with a pure tone sound or with a
composite form of sound, with many frequencies presented at once.
Tests can also be performed on the hearing aid while it is worn on an actual ear. In
this test, the sound is provided by a sound field speaker and controlled by means
of a reference microphone placed in close proximity to the test ear and hearing aid.
The sound from the hearing aid is measured by a thin hollow silicone rubber probe
tube that is placed in the ear next to and typically along side of the hearing aid ear
mold in order to pick up the sound generated by the hearing aid.
Tests can also be made of the battery current drain of the hearing aid while in coupler/sound chamber mode, using a special battery pill set that is used to substitute
for the battery normally used in the hearing aid. Typically, the current is measured
while the hearing aid is being driven by a calibrated sound.
Further tests can be made of the magnetic field sensitivity of a hearing aid operated
in telephone coil mode. This is done either by use of a built in coil in the sound
chamber of the FONIX 8000 or through external telephone coil.
Intended Use:
The FONIX 8000 has two major intended uses:
• To determine the functionality of a hearing aid. That is, to determine if the
hearing aid is functioning within the hearing aid manufacturer’s specifications with an acceptable frequency response, battery current drain, distortion, noise, and other characteristics as defined by the applicable standard.
• To determine the frequency response of the hearing aid and be able to compare this frequency response to a target based upon the patient’s hearing
threshold levels. These measurements can be performed as real-ear or coupler tests.