The FONIX FP35 Portable Hearing Aid Analyzer 
has many available options and accessories. Here's a description of the most popular ones.
Real-Ear Measurements
Real-ear measurements take the guesswork out of a hearing aid fitting. You find out the exact frequency response inside the patient's ear and how changes to the hearing aid fitting program effect the actual real-ear response.
Three different measurement screens as well as the Audiogram Entry screen are included with the Real-ear Option. This allows you to view the real-ear response in terms of Insertion Gain, Gain, or SPL by flipping through the different screens. In the Real-ear SPL screen, the patient's threshold values and uncomfortable values are displayed together with the real-ear response and target, making these measurements directly comparable.
Open Fit Coupler
The Open Fit coupler is designed to give you a realistic frequency response of an open fit hearing aid. The coupler is easy to use and doesn't require any putty or special attachments. The clinician puts the earpiece of the hearing aid into the coupler just as it would be inserted into the ear. The resulting frequency response is generally more like the real-ear response of the hearing aid than the response obtained from a standard 2-cc coupler.
CIC
When a CIC hearing aid is tested using a 2-cc HA-1 coupler, the frequency response, while conforming to ANSI specifications, is very misleading. These small hearing aids, placed deeply into the ear canal, provide a great deal more amplification in the patient's ear than is indicated by the 2-cc coupler response.
The CIC coupler, combined with software correction factors, provide a more realistic picture of what the frequency response inside the patient's ear will be. Real-ear measurements are the most accurate way of determining the amplification the patient is actually receiving, but the CIC Option is the next best thing.
External Monitor Connection
The External Monitor option needs to be included if you want to connect the FP35 to an external monitor for better viewing by the patient and others in the room. When enabled, the FP35 display is shown on both the internal LCD and the connected monitor. Just about any standard computer monitor is compatible, including a modern flat screen. This option consists of an internal circuit board that is installed into the FP35 analyzer. It does not include the external monitor itself.
