To determine if a directional microphone hearing aid is working properly.

Procedure:

Part 1:
Using multicurve on the Fonix 6500-CX, run a hearing aid at 4 different settings comprising of different levels and/or signal types.

Writeup:

1. Properly display printouts and explain what conditions you chose.

Part 2:
Using the Fonix FP40, present a 90 dB complex signal with a directional microphone facing toward and away from the speaker. Using an omnidirectional hearing aid, run in the same conditions. Use a multicurve plot to show comparisons.

Writeup:

1. Properly display strips showing verification of a directional microphone and an omnidirectional microphone.

2. Explain why this measurement would be useful in hearing aid verification process.