Dr. Robert Martin, author of Hearing Journal’s Nuts and Bolts column, shows how the FONIX FP35 Touch can demonstrate hearing aid problems to a hearing impaired patient. Please click on the following link to see the 4 minute video. After you have seen him perform his magic, continue reading below to see the actions he took to make his analysis.
How did he do this so quickly?
This video displays a conversation between Dr. Martin and Terry McDonald, who is asking about hearing aid hearing problems. Using the FP35 Touch, Dr. Martin enters Terry’s audiogram and UCL, and then tests the aid in two different ways. He also explains what he is doing as he works. He is quite adept in his operation of the analyzer, taking advantage of its ability to provide accurate but quick answers to measurement questions. The below explanation outlines the Dr. Martin’s actions.
Opening the video:
As the video starts, the FP35 Touch screen is open to the Real ear audiometric entry AP. Dr. Martin uses the touch features on the FP35 Touch’s screen. He has connected a monitor to the analyzer so that his patients can view what is going on.
Entering the Audiogram and UCL values
After Terry explains his hearing aid problems, Dr. Martin uses a stylus and touches the graphical screen to enter Terry’s audiogram and then corrects the numbers; the whole process of audiogram entry takes roughly twenty seconds. The UCL entry is done by touching the UCL column in the data box and then touching the graph to enter the values from Terry’s audiogram.
He then explains what he has entered to Terry. Displayed are a charts of Terry’s hearing threshold and sounds that are uncomfortably loud.
Testing the hearing aid against the HL/UCL graphs
Dr. Martin now wants to run Terry’s hearing aid through some tests to determine how the aid performs as compared with Terry’s hearing threshold and UCL.
Dr. Martin switches the system from real ear to coupler measures, choosing the ear simulator AP, in which the HL and UCL values are mapped over to coupler measured SPL values. Conversions from HL to SPL are automatically done using standard tables.
The switch is done with two quick touch moves. The first is to bring up the FP35 Touch AP map by pressing the stylus to the surface of the screen for 2 seconds. Then he touches the desired EAR SIM AP with the stylus, causing it to be loaded. The screen starts out displaying coupler tests in gain.
He sets the volume control of the aid and connects it to a standard HA2 2CC coupler. He uses a digital speech system of analysis, starting with a low level of 50 dB SPL. The test is started either by touching the START label on the lower left hand side of the screen or pressing the analyzer’s START button. He then explains the result, as the hearing aid fails to supply sound loud enough to reach Terry’s threshold values above 1000 Hz.
He then readjusts the gain of the aid for a “church “setting, changes the signal type to a pure tone sweep and raises the level to 90 dB SPL to check for UCL output. To do these actions, he touched the source box, which brings up a small menu displaying available source types. He then chooses the NORM pure tone sweep signal by touch, and then touches the screen, to set the choice. The output level is changed by touching the source box and then choosing “90″ from the displayed list of possible levels.
The hearing aid output with this form of drive is above the UCL values that were mapped over from the audiogram that was entered earlier.
The discussion concludes with Dr. Martin explaining the problems with Terry, who then agrees that changes are needed.
A listing of FP35 Touch commands used:
Start out with audiometric real ear screen displayed.
1. Touch to do graphical entry and correction of HTL values
2. Touch the HTL list box to change the screen edit function
- Touch to do Graphical entry and correction of UCL values
3. A 2 second press on the screen surface to bring up the “APMAP”
- Load the COUPLER EAR SIM AP with a touch.
- Source level was preset to 50 dB SPL and display to aid gain.
- Mount the aid to the HA2 2CC coupler. Place into chamber for test.
4. Start the test and note results.
5. Switch display from gain to SPL by touching SPL label at top left corner of graph.
6. Touch Source box above F4 and touch NORM.
- Touch screen to set the source choice.
7. Touch source level box to bring up a list of levels.
- Choose 90 by a Touch.
- Adjust the aid control.
8. Press Start to run the pure tone test.
Play the video again and try to see him perform these actions.