Frye FP35 Manual

A SERVICE OF

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164 FONIX FP35 Hearing Aid Analyzer

•Hearingaidinbetterear,on, set at use gain

•Transmitteronbadsideturnedoff

•Loudspeakerat90º,12inchesfrombadear

Aided—Measurement of “better” ear canal (baffle overcome by aid)

Same setup as above, except

•Transmitteronbadsideturnedon

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

of adding the second microphone for sound arriving from the “bad” side.

5.9.3 Measuring Overall Insertion Gain

The methods for measuring the overall insertion gain of CROS and BICROS aids

are described in this section.

Since it has not been shown for CROS and BI-CROS instruments that a 45º

position of the loudspeaker improves the reliability of insertion gain measure-

ments, we recommend a 45º position of the loudspeaker only for monaural

instruments, and a 0º position for CROS and BI-CROS instruments.

5.9.3.1 CROS

Unaided—Measurement of “good” ear

Set up the FP35 analyzer as follows.

•ReferencemicrophoneON

•SoundfieldLEVELED

•Referencemicrophoneoverpinnaof

bad ear

•Probemicrophoneinsideunoc-

cluded ear canal of good ear

•Loudspeakerat0º,12inchesfrom

bridge of nose

Aided—Measurement of “good” ear

Same setup as above, except:

•Aidinplaceingoodearandsettousergain.

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

benefit of inserting the hearing aid.

REFERENCE MIC

PROBE MIC

12"

SPEAKER

GOOD

EAR

BAD

EAR