Rev 2009-03-24
Rev 1 calculation:
^ Soft Gain (Response) ^ VC Range ^ | 50dB - 120dB | 40dB | | 40dB - 49dB | 30dB | | 0dB - 39dB | 10dB |
* if avg Soft Gain (Response) > = 50dB, then VC Range = 40dB * else if avg Soft Gain (Response) > = 40dB, then VC Range = 30dB * else VC Range = 10dB
Rev 2 calculation:
Soft Gain (Response) | VC Range |
---|---|
41dB - 120dB | 40dB |
31dB - 40dB | 30dB |
21dB - 30dB | 20dB |
0dB - 20dB | 10dB |
Rev 3 (2009-07-10) calculation:
^ Soft Target ^ VC Range ^ | 41dB - 120dB | 40dB | | 31dB - 40dB | 30dB | | 21dB - 30dB | 20dB | | 0dB - 20dB | 10dB |
* if Avg Soft Target > 40dB, then VC Range = 40dB * else if Avg Soft Target > 30dB, then VC Range = 30dB * else if Avg Soft Target > 20dB, then VC Range = 20dB * else VC Range = 10dB
NOTE: Using Soft Target (as opposed to Soft Response Gain) allows using a stable reference for calculating the VC Range before running an Autofit. Using the Soft Response Gain requires performing an Autofit first (to obtain the response curves), and then calculating the VC Range based on those curves. The problem that emerges from the latter is when the VC Range modifies the response curves. In Intricon products, the response curve is kept in the middle of the VC Range. So for a 20 dB range, the response curve has +10 dB and - 10 dB. For a 50 dB range, it gets modified to have +25 dB and -25 dB, but the response curve is changed as well, no longer matching the autofitted response curve.
Formula for matching 3kHz or appropriate peak. In summary:
Example code:
EqMax := NzBase.GetParamMax('BEQ1_gain'); TargetCurve := sdSoft; Case TargetCurve of sdSoft: TargetCurveValue := 40; sdModerate: TargetCurveValue := 60; else TargetCurveValue := 80; end; // Adjust GC/VC to match Soft target at 3000 Hz. // However, if HearingLossThreshold at 500Hz > HearingLossThreshold at 1000Hz, // and HearingLossThreshold at 1000Hz > HearingLossThreshold at 2000Hz, skip // {if (Audiogram.Values[fq500] <= Audiogram.Values[fq1000]) or // (Audiogram.Values[fq1000] <= Audiogram.Values[fq2000]) then} // Get frequency of peak gain HighestFreq := fq3000; if Audiogram.Values[HighestFreq] < Audiogram.Values[fq2000] then HighestFreq := fq2000; if Audiogram.Values[HighestFreq] < Audiogram.Values[fq1000] then HighestFreq := fq1000; if Audiogram.Values[HighestFreq] < Audiogram.Values[fq500] then HighestFreq := fq500; // Get avg HearingLossThreshold AvgThres := (Audiogram.Values[fq500] + Audiogram.Values[fq1000] + Audiogram.Values[fq2000] + Audiogram.Values[fq3000]) div 4; // compare avg HearingLossThreshold to audiogram values at 3kHz and Peak frequency if (Audiogram.Values[fq3000]-AvgThres) >= (Audiogram.Values[HighestFreq]-AvgThres) then begin // if freq3000 contains peak, we simply adjust GC/VC to match Soft Target at 3000 Hz. AdjustParam(TargetCurve, 'matrix_gain', 0, 47, 1, 47 {2.997kHz}, TargetCurveValue); end else begin // if frequencies other than freq3000 contains peak gain, // we adjust GC/VC to match Soft Target at that other frequency. Case HighestFreq of fq500 : AdjustParam(TargetCurve, 'matrix_gain', 0, 47, 1, 16 {500Hz}, TargetCurveValue); fq1000: AdjustParam(TargetCurve, 'matrix_gain', 0, 47, 1, 28 {1000Hz}, TargetCurveValue); fq2000: AdjustParam(TargetCurve, 'matrix_gain', 0, 47, 1, 40 {2000Hz}, TargetCurveValue); end; // Match equalizers frequencies to Soft Target from 5.2 - 7.2 kHz. SetParamValue('BEQ10_gain', FindBestMatch(TargetCurve, 'BEQ10_gain', 0, EqMax, 57 {5339Hz}, TargetCurveValue), False); // 5.2 kHz SetParamValue('BEQ11_gain', FindBestMatch(TargetCurve, 'BEQ11_gain', 0, EqMax, 60 {6350Hz}, TargetCurveValue), False); // 6.5 kHz SetParamValue('BEQ12_gain', FindBestMatch(TargetCurve, 'BEQ12_gain', 0, EqMax, 62 {7127Hz}, TargetCurveValue), False); // 7.2 kHz end;
Autofit routine dependencies:
Enable autofit on Half Shell and Full Shell products only, and having Adaptive Directional microphones: — Jenny Sudduth 2008/09/08 12:50
* Custom Settings: * Sparo, SparoAD (all Open Fit perhaps?): MPO = -8dB
— Jenny Sudduth 2008/09/08 16:11 - Make all styles the same
Abbreviation | Term |
---|---|
AGC-o | Automatic Gain Control (output) |
Avg | Average |
BTE | Behind-the-Ear instrument |
Ch | Channel |
CR | Compression Ratio |
dB | Decibels |
Freq | Frequency |
HL | Hearing Level (or Loss) as depicted in an Audiogram (aka HTL) |
HTL | Hearing Threshold Level as depicted in an Audiogram (aka HL) |
Hz | Hertz |
kHz | KiloHertz |
MPO | Maximum Power Output |
OTE | Other-the-Ear instrument |
RIC | Receiver-in-Canal instrument |
SRT | Speech Reception Threshold |
TK | Threshold Kneepoint |
VC | Volume Control |