MedRx AVANT REM (Real Ear Measurement) Training Manual
Effective Date: 05-25-2017
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Additional Tests & Features
Real Ear to Coupler Difference (RECD)
The Real Ear to Coupler Difference (RECD) is used to simulate real ear measurements by
coupler measurements and is useful when fitting children or “difficult” to fit patients. RECD
measurements can be conducted outside of a Hearing Instrument Test Box when using the
optional MedRx RECD Coupler.
The RECD values are used as a correction to coupler measures for that client’s hearing
instruments. By performing all subsequent measures in the coupler and applying the RECD
corrections to the coupler measures, the “real ear” factors are incorporated into the results.
The resulting simulated measurements provide information to select and make adjustments
to the hearing instrument and verify adjustments in the MedRx coupler rather than in the
uncooperative client’s ear. This is particularly important in the case of children, whose small
volume ear canals enhance high frequency amplification more so than in average adults. This
is an essential consideration in determining the maximum output of the hearing instrument.
If RECD data is present, the software will display an option to choose between Ear or Coupler
measurement on all Real Ear screens where measurements in a coupler are appropriate.
There are two ways to measure the REAR response with optional RECD coupler: using an
insert headphone or a hearing instrument.
If a hearing instrument is used, its volume control setting and other parameters should
remain the same
for both REAR and coupler measurements. Set the volume control to
moderate, and turn the compression and noise reduction circuits off.
Using open-fit hearing aids for RECD measurements may result in invalid low and mid-
frequency measurements because of insufficient gain at those frequencies. Please contact
your hearing aid manufacturer for recommendations.
