Formant Excitation_to_Formant (Excitation me, int maxnFormants)
{
Formant thee = NULL;
long i, nfreq = my nx, nform = 0;
double *p = my z [1];
thee = Formant_create (0, 1, 1, 1, 0.5, maxnFormants); if (! thee) return NULL;
thy frame [1]. formant = NUMstructvector (Formant_Formant, 1, maxnFormants);
for (i = 2; i < nfreq; i ++)
if (p [i] > p [i - 1] && p [i] >= p [i + 1])
{
double min3phon, left, right;
double firstDerivative = p [i+1] - p [i-1], secondDerivative = 2 * p [i] - p [i-1] - p [i+1];
long j;
Formant_Formant formant = & thy frame [1]. formant [++ nform];
formant -> frequency = Excitation_barkToHertz (
my x1 + my dx * (i - 1 + 0.5 * firstDerivative / secondDerivative));
min3phon = p [i] + 0.125 * firstDerivative * firstDerivative / secondDerivative - 3.0;
/* Search left. */
j = i - 1; while (p [j] > min3phon && j > 1) j --;
left = Excitation_barkToHertz (
p [j] > min3phon ? my xmin : my x1 + my dx * (j - 1 + (min3phon - p [j]) / (p [j + 1] - p [j])));
/* Search right. */
j = i + 1; while (p [j] > min3phon && j < nfreq) j ++;
right = Excitation_barkToHertz (
p [j] > min3phon ? my xmax : my x1 + my dx * (j - 1 - (min3phon - p [j]) / (p [j - 1] - p [j])));
formant -> bandwidth = right - left;
if (nform == thy maxnFormants) break;
}
thy frame [1]. nFormants = nform;
return thee;
}
autoFormant Excitation_to_Formant (Excitation me, int maxnFormants) {
try {
long nfreq = my nx, nform = 0;
double *p = my z [1];
autoFormant thee = Formant_create (0, 1, 1, 1, 0.5, maxnFormants);
thy d_frames [1]. formant = NUMvector <structFormant_Formant> (1, maxnFormants);
for (long i = 2; i < nfreq; i ++)
if (p [i] > p [i - 1] && p [i] >= p [i + 1]) {
double min3phon, left, right;
double firstDerivative = p [i+1] - p [i-1], secondDerivative = 2 * p [i] - p [i-1] - p [i+1];
long j;
Formant_Formant formant = & thy d_frames [1]. formant [++ nform];
formant -> frequency = Excitation_barkToHertz (
my x1 + my dx * (i - 1 + 0.5 * firstDerivative / secondDerivative));
min3phon = p [i] + 0.125 * firstDerivative * firstDerivative / secondDerivative - 3.0;
/* Search left. */
j = i - 1; while (p [j] > min3phon && j > 1) j --;
left = Excitation_barkToHertz (
p [j] > min3phon ? my xmin : my x1 + my dx * (j - 1 + (min3phon - p [j]) / (p [j + 1] - p [j])));
/* Search right. */
j = i + 1; while (p [j] > min3phon && j < nfreq) j ++;
right = Excitation_barkToHertz (
p [j] > min3phon ? my xmax : my x1 + my dx * (j - 1 - (min3phon - p [j]) / (p [j - 1] - p [j])));
formant -> bandwidth = right - left;
if (nform == thy maxnFormants) break;
}
thy d_frames [1]. nFormants = nform;
return thee;
} catch (MelderError) {
Melder_throw (me, U": not converted to Formant.");
}
}
autoExcitation Spectrum_to_Excitation (Spectrum me, double dbark) {
try {
long nbark = (int) floor (25.6 / dbark + 0.5);
double *re = my z [1], *im = my z [2];
autoNUMvector <double> auditoryFilter (1, nbark);
double filterArea = 0;
for (long i = 1; i <= nbark; i ++) {
double bark = dbark * (i - nbark/2) + 0.474;
filterArea += auditoryFilter [i] = pow (10, (1.581 + 0.75 * bark - 1.75 * sqrt (1 + bark * bark)));
}
/*for (long i = 1; i <= nbark; i ++)
auditoryFilter [i] /= filterArea;*/
autoNUMvector <double> rFreqs (1, nbark + 1);
autoNUMvector <long> iFreqs (1, nbark + 1);
for (long i = 1; i <= nbark + 1; i ++) {
rFreqs [i] = Excitation_barkToHertz (dbark * (i - 1));
iFreqs [i] = Sampled_xToNearestIndex (me, rFreqs [i]);
}
autoNUMvector <double> inSig (1, nbark);
for (long i = 1; i <= nbark; i ++) {
long low = iFreqs [i], high = iFreqs [i + 1] - 1;
if (low < 1) low = 1;
if (high > my nx) high = my nx;
for (long j = low; j <= high; j ++) {
inSig [i] += re [j] * re [j] + im [j] * im [j]; // Pa2 s2
}
/* An anti-undersampling correction. */
if (high >= low)
inSig [i] *= 2.0 * (rFreqs [i + 1] - rFreqs [i]) / (high - low + 1) * my dx; // Pa2: power density in this band
}
/* Convolution with auditory (masking) filter. */
autoNUMvector <double> outSig (1, 2 * nbark);
for (long i = 1; i <= nbark; i ++) {
for (long j = 1; j <= nbark; j ++) {
outSig [i + j] += inSig [i] * auditoryFilter [j];
}
}
autoExcitation thee = Excitation_create (dbark, nbark);
for (long i = 1; i <= nbark; i ++) {
thy z [1] [i] = Excitation_soundPressureToPhon (sqrt (outSig [i + nbark/2]), Sampled_indexToX (thee.get(), i));
}
return thee;
} catch (MelderError) {
Melder_throw (me, U": not converted to Excitation.");
}
}
Cochleagram Sound_to_Cochleagram_edb
(Sound me, double dtime, double dfreq, int hasSynapse, double replenishmentRate,
double lossRate, double returnRate, double reprocessingRate)
{
try {
double duration_seconds = my xmax;
if (dtime < my dx) dtime = my dx;
long ntime = floor (duration_seconds / dtime + 0.5);
if (ntime < 2) return NULL;
long nfreq = floor (25.6 / dfreq + 0.5); // 25.6 Bark = highest frequency
autoCochleagram thee = Cochleagram_create (my xmin, my xmax, ntime, dtime, 0.5 * dtime, dfreq, nfreq);
/* Stages 1 and 2: outer- and middle-ear filtering. */
/* From acoustic sound to oval window. */
for (long ifreq = 1; ifreq <= nfreq; ifreq ++) {
double *response = thy z [ifreq];
/* Stage 3: basilar membrane filtering by gammatones. */
/* From oval window to basilar membrane response. */
double midFrequency_Bark = (ifreq - 0.5) * dfreq;
double midFrequency_Hertz = Excitation_barkToHertz (midFrequency_Bark);
autoSound gammatone = createGammatone (midFrequency_Hertz, 1 / my dx);
autoSound basil = Sounds_convolve (me, gammatone.peek(), kSounds_convolve_scaling_SUM, kSounds_convolve_signalOutsideTimeDomain_ZERO);
/* Stage 4: detection = rectify + integrate + low-pass 500 Hz. */
/* From basilar membrane response to firing rate. */
if (hasSynapse) {
double dt = my dx;
double M = 1; /* Maximum free transmitter. */
double A = 5, B = 300, g = 2000; /* Determine permeability. */
double y = replenishmentRate; /* Meddis: 5.05 */
double l = lossRate, r = returnRate; /* Meddis: 2500, 6580 */
double x = reprocessingRate; /* Meddis: 66.31 */
double h = 50000; /* Convert cleft contents to firing rate. */
double gdt = 1 - exp (- g * dt), ydt = 1 - exp (- y * dt),
ldt = (1 - exp (- (l + r) * dt)) * l / (l + r),
rdt = (1 - exp (- (l + r) * dt)) * r / (l + r),
xdt = 1 - exp (- x * dt);
double kt = g * A / (A + B); /* Membrane permeability. */
double c = M * y * kt / (l * kt + y * (l + r)); /* Cleft contents. */
double q = c * (l + r) / kt; /* Free transmitter. */
double w = c * r / x; /* Reprocessing store. */
for (long itime = 1; itime <= basil -> nx; itime ++) {
double splusA = basil -> z [1] [itime] * 10 + A;
double replenish = M > q ? ydt * (M - q) : 0;
double eject, loss, reuptake, reprocess;
kt = splusA > 0 ? gdt * splusA / (splusA + B) : 0;
eject = kt * q;
loss = ldt * c;
reuptake = rdt * c;
reprocess = xdt * w;
q = q + replenish - eject + reprocess;
c = c + eject - loss - reuptake;
w = w + reuptake - reprocess;
basil -> z [1] [itime] = h * c;
}
}
if (dtime == my dx) {
for (long itime = 1; itime <= ntime; itime ++)
response [itime] = basil -> z [1] [itime];
} else {
double d = dtime / basil -> dx / 2;
double factor = -6 / d / d;
double area = d * sqrt (NUMpi / 6);
double expmin6 = exp (-6), onebyoneminexpmin6 = 1 / (1 - expmin6);
for (long itime = 1; itime <= ntime; itime ++) {
double t1 = (itime - 1) * dtime, t2 = t1 + dtime, mean = 0;
long i1, i2;
long n = Matrix_getWindowSamplesX (basil.peek(), t1, t2, & i1, & i2);
Melder_assert (n >= 1);
if (n <= 2) {
for (long isamp = i1; isamp <= i2; isamp ++)
mean += basil -> z [1] [isamp];
mean /= n;
} else {
double mu = floor ((i1 + i2) / 2.0);
long muint = mu, dint = d;
for (long isamp = muint - dint; isamp <= muint + dint; isamp ++) {
double y = 0;
if (isamp < 1 || isamp > basil -> nx)
Melder_casual ("isamp %ld", isamp);
else
y = basil -> z [1] [isamp];
mean += y * onebyoneminexpmin6 * (exp (factor * (isamp - muint) *
(isamp - muint)) - expmin6);
}
mean /= area;
}
response [itime] = mean;
}
}
}
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, ": not converted to Cochleagram (edb).");
}
}
