formants

Format tracking algorithm.

Usage

formants(cf, ca, f0, mflag, bias, lmin)

cf

a matrix containing the frequencies of the formant candidates in Hz

• each row of cf contains the candidates of one frame

if cf[i,k]=0 (0<=i<N, 0<=k<M) the number of candidates in frame i equals k

the frequencies of frame i must be in ascending order: cf[i,j]<cf[i,j+1] (0<=j<k-1)

• number of frames: N=nrow(cf)
• maximum number of candidates M=ncol(cf)

ca

a matrix containing the amplitudes of formant candidates in dB

• ca must be a matrix with the same dimensions as cf
  or a scalar, if amplitudes should not be used for formant tracking

f0

f0 vector

• f0 must be a vector with length N containing the f0 values int Hz
  or a scalar, if f0 should not be used for formant tracking
• if f0 is supplied, the formant tracking is only applied to voiced regions

mflag

selects the tracking method

• currently only one method (mflag=0) is implemented (see sp-atom FORMANTS for more details)
• a second method using a formant modell is under development

bias

tracking bias in Hz

lmin

the minimum length of a track in frames

Result

A matrix with N rows and L columns. Each column l contains the formant track with order l+1. L is the maximum formant order or the maximum number of parallel tracks.

See also

f0ac, lpc, cepstrum, ipeak, FORMANTS

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