


LXPNEW(1)                USER COMMANDS                  LXPNEW(1)



NAME
     lxpnew  -  extract  parameters  describing  each  excitation
     period from laryngograph waveform

SYNOPSIS
     lxpnew (-I) (-T thresh) (-H height) (-A area) (-R ratio) (-S
     sensitivity) (-i item) (-F maxfreq) file

DESCRIPTION
     lxpnew is a program to extract  parameters  describing  each
     excitation  period  from the laryngograph waveform. It first
     identifies the closure points  in  an  identical  manner  to
     tx(1),  then  for  each  excitation period as defined by the
     closure points calculates  the  following  parameters  (each
     stored as an integer):

     1)         period duration in frames;

     2)         closed  phase  duration  in  frames,  calculating
                point  of  opening  as  most  negative  value  of
                differenced lx in current cycle; opening side  of
                lx  waveform  is  modelled  by  a  polynomial for
                greater smoothness.

     3)         open phase duration in frames, calculating  point
                of opening likewise.

     4)         closed  phase  duration  in  frames,  calculating
                point  of  opening as that which divides lx range
                in current excitation period such  that  (max  lx
                value - opening lx value):(opening lx value - min
                lx value) is ratio given by -R parameter;

     5)         open phase duration in frames, calculating  point
                of opening likewise;

     6)         height of peak of differenced lx waveform at clo-
                sure (arbitrary units);

     7)         amplitude  of  lx  waveform,  i.e.  lx  range  in
                current excitation period (normalised by dividing
                by average amplitude over sample, and  multiplied
                by 100000 for storage as an integer);

     8)         closed  phase  duration  in  frames,  calculating
                point  of  opening as that at which lx signal has
                same value as at previous closure.

     Options and their meanings are:

     -I         Identify program and exit.




SPAR                    Last change: UCL                        1






LXPNEW(1)                USER COMMANDS                  LXPNEW(1)



     -Tthresh   Threshold  factor  for  peak  detection  (default
                1.0).

     -Hheight   Height  factor  for  peak  significance  (default
                4.0).

     -Aarea     Area factor for peak significance (default 6.0).

     -Ssensitivity
                Sensitivity of peak  detection:  the  larger  the
                value,  the more peaks are likely to be detected.
                Users are advised that -S is easier to  use  than
                -T, -H or -A. Default 1.0.

     -Rratio    Ratio in which opening point divides range of  Lx
                in current cycle (default 2.333, i.e. 7:3).

     -Fmaxfreq  Specify maximum frequency, in Hz,  to  be  recog-
                nised by program; default 800Hz.

     -iitem     Select input item type & subtype.

INPUT ITEMS
     2.xx       Any excitation waveform item

OUTPUT ITEMS
     3          Tx and other Lx parameters

VERSION/AUTHOR
     (version numbers follow those of lxp(1)) 3.0 - Peter Davies.
     Includes amendment to correct "zero closed phase" .

     3.1 - adds sensitivity & max freq options.

     3.2 - adds sfs file handling.

     3.3 - models opening lxp for greater  smoothness  of  params
     (2) & (3);
           stores closed phase duration by 3rd  method  in  param
     (8).

BUGS
SOURCE
     /users/mark/sfs/man/../ucl-priv/lxpnew.c











SPAR                    Last change: UCL                        2



