Recd Measurements - Interacoustics Affinity 2.0 Additional Information

2.0
Affinity Additional Information Page 183
2.7.4

RECD Measurements

RECD (Real-Ear to Coupler Difference): The RECD accounts for the difference in decibels (dB) across
frequencies, between the SPL measured in the real-ear and in a 2cc coupler, produced by a transducer
generating the same signal.
Example at 1000 Hz:
Coupler SPL – Real-Ear SPL = RECD
In this example 25 dB SPL is measured in the 2 cc coupler and 30 dB SPL was measured in the ear. This
means that we have a real-ear to coupler difference of 5 dB SPL at 1000 Hz.
COUPLER MEASURE
EAR MEASURE
You are performing a measurement to compare two entities; a known volume size (the coupler) and an
unknown volume size (the ear canal). This is important to do with clients whose ear canals are not the
standard 2cc in volume. For example, children or adults who have had surgical procedures. The difference
measurement obtained between the ear and coupler provides individual information about the ear canal
which can be used in the hearing aid fitting. It can be utilized to estimate 2cc coupler targets which means
you can not only test on the ear but also based on the RECD values the verification can be performed in the
test box instead of the client's ear. This is particularly useful with children.
Note: When an RECD is measured the REM440 automatically switches to test box/coupler verification mode
(simulated REM).
The REM440 module provides a guided RECD procedure making sure no mistakes are made.