Frye FP35 Manual

A SERVICE OF

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General Operation 39

2.5.2.1 Filter Type

Filters are the type of speech weighting applied to the test signals as they are

presented to the hearing aid. By default, the FP35 analyzer automatically

chooses the appropriate speech weighting to use with a particular type of signal.

For instance, when you use a pure-tone signal, a flat weighting is used. That is,

every frequency of the pure-tone sweep has the same amplitude. When you use

the composite signal, the Frye ANSI speech weighting is used. That is, the low

frequencies have higher amplitudes than the higher frequencies.

The FP35 allows you to specifically choose the type of speech weighting you

want to use. You do this by altering the FILTER selection in the Advanced Menu

of the Coupler Multicurve Screen and the Real-Ear Measurement Screens. Here

is an explanation of the available filter selections:

• FLAT—No speech weighting used. All frequencies have the same ampli-

tude.

• ANSI—The standard Frye composite signal weighting which starts 3 dB

down at 900 Hz and continues to roll off the high frequencies at a rate of

6 dB per octave.

• ICRA—The speech weighting taken from the CD of sounds developed by

the International Collegium of Rehabilitative Audiology.

• C-LTASS—The child long term average speech spectrum used by the

University of Western Ontario in their DSL fitting method.

• A-LTASS—The adult long term average speech spectrum used by the

University of Western Ontario in their DSL fitting method.

• ANSI-92—The speech weighting specified in the ANSI S3.22-1992 stan-

dard. It is very similar to the ANSI weighting except that it contains a

low frequency filter at 200 Hz.

When AUTO is selected, the following filters are automatically applied:

Coupler Multicurve Screen:

• FLATwithpure-tonesignal

• ANSIwithComposite/DigitalSpeechsignal

Real-Ear SPL Screen:

• FLATwithpure-tonesignalabove85dBSPL

• ANSIwithnon-DSLfittingrule(allothersignaltypes)

• A-LTASSwithDSLfittingruleforadults(allothersignaltypes)

• C-LTASS with DSL fitting rule for children (all other signal types)

Real-Ear Unaided & Aided Screen and Insertion Gain Screen:

• FLATwithnon-DSLfittingruleandpure-tonesignal

• ANSIwithnon-DSLfittingruleandComposite/DigitalSpeechsignal