TXSTAT
NAME
txstat -- calculate Tx statistics of jitter and shimmer
SYNOPSIS
txstat
(-i item) (-j|-J jittersize) (-s|-S shimmersize) (-f framerate) file
DESCRIPTION
txstat
is a program to calculate some statistics of a tx item and to
report the results as track items. Output is
on 5ms frames (200 frames/sec) but may be changed by a command line
option. Jitter is a measure of pitch pertubation on a cycle to cycle
basis. The duration of each pitch period T is compared to the average
of the N surrounding pitch periods and scaled according to
100.0*abs(1-T/averageT). By default N=5.
Shimmer is a measure of amplitude perturbation on a cycle
to cycle basis using an equivalent formula based on the
maximum signal amplitude over the pitch period A compared
to the average of the N surrounding pitch periods:
100.0*abs(1-A/averageA).
Default operation is to calculate both jitter and shimmer.
Options
and their meanings are:
-I
Identify program and version number.
-i item
Select input item.
-j
Calculate jitter track.
-J jittersize
Change number of pitch cycles used in computation. Default 5.
-s
Calculate shimmer track.
-S shimmersize
Change number of pitch cycles used in computation. Default 5.
-f sfreq
Select sampling frequency of track items. Default 200.
INPUT ITEMS
SP.xx
Speech waveform used for shimmer measurement.
TX.xx
Any excitation period data item.
OUTPUT ITEMS
TR
Jitter track.
TR
Shimmer track.
VERSION/AUTHOR
1.0
Mark Huckvale
BUGS
Tracks are sampled, not averaged.
Fri Jul 09 14:54:44 2004