9
Feedback Management Tool
The Feedback Management tool (FBM) tool shows a graph with a marked Feedback Area. There is a high
likelihood of feedback occuring if the prescribed Insertion Gain falls within this area. This area is used in
the initial prescribing algorithm to prescribe a setting without feedback when the fitting session opens.
The Test curve (Simulated Insertion Gain) will follow the Target P1 curve (Target Insertion Gain) in the
Low Frequencies to fulfil the requirement of the selected rationale. However, in the High Frequencies the
Test curve will avoid entering the Feedback Area to prevent unrealistically high gain causing feedback. If
the Test (actual) curve is prescribed within this area then it is likely that there will be feedback unless the
earmould is very tight.
When running the FBM tool a Measured Feedback Area will be reset to match the client's own earmould.
The Feedback Area will either be enlarged or reduced depending on the tightness of the earmould.
Fitting tips:
The FBM tool is a routine to optimize
the settings of the instrument in
relation to feedback. This routine
preserves the frequency response
as far as possible, but if feedback is
encountered and is adjusted for, then
the FBM routine may change the
settings for the A-Gram, Crossover
Frequency, Gain and Volume Control.
In the fitting screen the trimmer,
unlike the FBM tool, only makes
adjustments to the VC level beyond
which the high frequency gain
will no longer be increased (it does
not change the setting or the other
trimmers to provide a better
response).
Summary of Contents for Sumo XP
Page 1: ...Fitting Guide Sumo XP...
Page 2: ......
