Frye FP35 Manual

A SERVICE OF

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Real-Ear Measurements 165

5.9.3.2 BI-CROS

Unaided—Measurement of “better” ear

Set up the FP35 analyzer as follows:

•ReferencemicrophoneON

•SoundfieldLEVELED

•UnaidedresponseCUSTOM

•Referencemicrophoneoverpinnaof

bad ear

•Probemicrophoneinsideunoc-

cluded ear canal of better ear

•Loudspeakerat0º,12inchesfrom

bridge of nose

Aided—Measurement of “better” ear

Same setup as above, except…

•Completeaidinplaceinbetterearandsetatusegain

•Bothtransmitterson

The difference curve, labeled “Insertion Gain” on the screen, shows the overall

benefit of inserting the hearing aid.

5.9.4 Measuring Insertion Loss to the “Good” Ear (CROS)

The method for measuring insertion loss in the patient’s “good” ear is described

in this section. They are the same for CROS and BICROS hearing aids.

When a CROS aid has been prescribed to overcome a severe unilateral high-

frequency loss, you may want to ensure that inserting an open ear mold into the

good ear has not significantly attenuated the acoustic transmission to the good

ear.

Since this is a monaural measurement, a 45º position of the loudspeaker is rec-

ommended.

Unaided—Unoccluded Ear canal Response of “good” ear

Set up the FP35 analyzer as follows.

•ReferencemicrophoneON

•SoundfieldLEVELED

•UnaidedCUSTOM

•Referencemicrophoneoverpinnaofgoodear

BETTER

EAR

REFERENCE MIC

PROBE MIC

12"

BAD

EAR

SPEAKER