public void CalculateTubeCoefficients(IntonationModel model, ThroatModelParameters parameters)
{
/* CALCULATE COEFFICIENTS FOR THE Oropharynx */
for (int i = 0; i < OropharynxCoefficients.Count(); i++)
{
var lastSegment = i + 1 == OropharynxCoefficients.Count();
var radA2 = Square(model.RadiusSegments.ElementAt(i));
var radB2 = lastSegment ? Square(parameters.AperatureScalingRadius) : Square(model.RadiusSegments.ElementAt(i + 1));
OropharynxCoefficients[i] = (radA2 - radB2) / (radA2 + radB2);
}
/* CALCULATE ALPHA COEFFICIENTS FOR 3-WAY JUNCTION */
var sides = Square(model.RadiusSegments.ElementAt(3));
var velum = Square(model.Velum);
var sum = 2.0 / (sides + sides + velum);
Alpha.Left = sum * sides;
Alpha.Right = sum * sides;
Alpha.Upper = sum * velum;
/* AND 1ST NASAL PASSAGE COEFFICIENT */
var nose = Square(parameters.NoseRadius.ElementAt(1));
NasalCoefficients[0] = (velum - nose) / (velum + nose);
}
private void InitializeThroat(ThroatModelParameters parameters, double sampleRate)
{
ta0 = (parameters.ThroatFreqCutoff * 2.0) / sampleRate;
tb1 = 1.0 - ta0;
throatGain = WaveHelper.CalculateAmplitude(parameters.ThroatVolume);
}
public VocalTract(ThroatModelParameters parameters, double nyquist, double sampleRate)
{
Oropharynx = Enumerable.Range(0, 10).Select(x => new TubeSection()).ToArray();
Nasal = Enumerable.Range(0, 6).Select(x => new TubeSection()).ToArray();
OropharynxCoefficients = new double[8];
NasalCoefficients = new double[6];
FricationTap = new double[8];
Alpha = new Junction();
InitializeMouthCoefficients((nyquist - parameters.MouthAperatureCoefficient) / nyquist);
InitializeNasalFilterCoefficients((nyquist - parameters.NoseAperatureCoefficient) / nyquist);
InitializeNasalCavity(parameters);
InitializeThroat(parameters, sampleRate);
}
public WaveTable(double sampleRate, ThroatModelParameters parameters)
{
Wavetable = new double[TABLE_LENGTH];
/* CALCULATE WAVE TABLE PARAMETERS */
_risePortion = (int)Math.Round(TABLE_LENGTH * (parameters.GlotPulseRiseTime / parameters.SectionLength));
_fallPortion = (int)Math.Round(TABLE_LENGTH * ((parameters.GlotPulseRiseTime + parameters.GlotPulseFallTimeMax) / parameters.SectionLength));
tnLength = _fallPortion - _risePortion;
tnDelta = Math.Round(TABLE_LENGTH * ((parameters.GlotPulseFallTimeMax - parameters.GlotPulseFallTimeMin) / parameters.SectionLength));
_basicIncrement = (double)TABLE_LENGTH / sampleRate;
CurrentPosition = 0;
int i, j;
if (parameters.GlotSrcType == GlotSrcType.Pulse)
{
/* CALCULATE RISE PORTION OF WAVE TABLE */
for (i = 0; i < _risePortion; i++)
{
double x = (double)i / (double)_risePortion;
double x2 = x * x;
double x3 = x2 * x;
Wavetable[i] = (3.0 * x2) - (2.0 * x3);
}
/* CALCULATE FALL PORTION OF WAVE TABLE */
for (i = _risePortion, j = 0; i < _fallPortion; i++, j++)
{
double x = (double)j / tnLength;
Wavetable[i] = 1.0 - (x * x);
}
/* SET CLOSED PORTION OF WAVE TABLE */
for (i = _fallPortion; i < TABLE_LENGTH; i++)
{
Wavetable[i] = 0.0;
}
}
else
{
/* SINE WAVE */
for (i = 0; i < TABLE_LENGTH; i++)
{
Wavetable[i] = Math.Sin(((double)i / (double)TABLE_LENGTH) * 2.0 * Math.PI);
}
}
}
private void InitializeNasalCavity(ThroatModelParameters parameters)
{
double radA2, radB2;
/* CALCULATE COEFFICIENTS FOR INTERNAL FIXED SECTIONS OF NASAL CAVITY */
for (int i = 0, j = 1; i < 4; i++, j++)
{
radA2 = Square(parameters.NoseRadius.ElementAt(i));
radB2 = Square(parameters.NoseRadius.ElementAt(i + 1));
NasalCoefficients[j] = (radA2 - radB2) / (radA2 + radB2);
}
/* CALCULATE THE FIXED COEFFICIENT FOR THE NOSE APERTURE */
radA2 = Square(parameters.NoseRadius.ElementAt(4));
radB2 = parameters.AperatureScalingRadius;
NasalCoefficients[5] = (radA2 - radB2) / (radA2 + radB2);
}