The Best Fit algorithm optimally adjusts all hearing device parameters to best approximate the targets for the selected fitting formula for inputs of 50, 65, and 80 dB SPL. The targets displayed are made up of six frequency points - 500, 1000, 1500, 2000, 3000, and 4000 Hz. The minimum frequencies required to perform a Best Fit are 500, 1000, 2000, and 4000 Hz. If audiometric threshold values are missing at 1500 or 3000 Hz, they will be interpolated.
In addition, Best Fit will set the adaptive features associated according to the hearing thresholds of the individual when the feature is available for the particular circuit chosen. This includes directional options with low frequency roll-off, feedback cancellation measures, voice/tonal indicator levels and noise management defaults.
Hearing instruments may be read without first entering audiometric data for the session, but Best Fit will be inactive until the minimum required audiometric data is entered or read from the hearing instrument.