txgen - generate open and close phase markers from lx


txgen (-I) (-i lx_item) (-d delay) (-h threshold) (-l threshold) file


txgen takes a laryngograph item and generates tx items for the open and close phase markers. The processing performed is as follows :- {PD} 0

1) Low-pass filter the Lx waveform at 3000Hz.

2) Differentiate the Lx waveform

3) Find maxima and minima of differentiated signal that lie above a threshold. These are taken as the positions of closure and opening on the lx waveform

4) The positions of larynx opening are determined as the next point in the lx waveform at amplitude equal to that at closure.

5) The markers may be corrected for the acoustic delay between lx and speech signals {PD}


-I Identify the program version and then exit.

-i item number and subtype for lx waveform.

-f Select low-pass filter cut-off frequency. Default 3000Hz.

-F Do not filter Lx.

-h Specify high threshold. Default 0.1 * maximum Lx difference.

-l Specify low threshold. Default 0.1 * minimum Lx difference.

-w Specify minimum peak width of differential in samples. Default 0.0001 of sample rate.

-d Acoustic delay in microseconds. Default 0us.


2.xx Any laryngograph signal


3.xx tx closed phase markers

3.xx tx open phase markers {PD}


1.0 David Pearce and Lynn Whitaker

2.0 David Pearce

3.0 Mark Huckvale

Fri Jul 09 14:54:44 2004