


TXGEN(1)                 USER COMMANDS                   TXGEN(1)



NAME
     txgen - generate open and close phase markers from lx

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

DESCRIPTION
     txgen takes a laryngograph item and generates tx  items  for
     the  open  and close phase markers. The processing performed
     is as follows :-
     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 posi-
          tions 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

     Options

     -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.

INPUT ITEMS
     2.xx       Any laryngograph signal

OUTPUT ITEMS
     3.xx       tx closed phase markers

     3.xx       tx open phase markers




SPAR                    Last change: GEC                        1






TXGEN(1)                 USER COMMANDS                   TXGEN(1)



VERSION/AUTHOR
     1.0  David Pearce and Lynn Whitaker

     2.0  David Pearce

     3.0  Mark Huckvale

SOURCE
     /ptemp/mark/sfs/contrib/ucl/txgen.c














































SPAR                    Last change: GEC                        2



