A crude script to obtain a graphical representation of a stereo sound waveform.

snd2png.sh

#!/bin/bash

INFILE="$1"
OUTFILE="$2"
DATFILE="${INFILE}.dat"
SVGFILE="${INFILE}.svg"

sox "${INFILE}" "${DATFILE}"
gnuplot << EOF
# set terminal pngcairo size 750,400 enhanced font 'Verdana,10'
# set output "${OUTFILE}"
  set terminal svg size 750,600 fname 'Verdana, Helvetica, Arial, sans-serif' fsize '12'
  set output "${SVGFILE}"

  set border linewidth 1.5
  set tics nomirror out
  set style line 11 lc rgb '#808080' lt 1 lw 2
  set style line 12 lc rgb '#808080' lt 1 lw 1 dt "."
  set xzeroaxis ls 12
  set border 3 back ls 11
  set nokey
  set style line 1 lc rgb '#000000' lt 1 lw 2 ps 1.5 
  set style line 2 lc rgb '#ad0000' lt 1 lw 2 ps 1.5

  set yrange [-1:+1]
  set multiplot layout 3,1 rowsfirst
    set xlabel "left channel"
    plot "${DATFILE}" using 1:2 title "left channel" with lines ls 1
    set xlabel "right channel"
    plot "${DATFILE}" using 1:3 title "right channel" with lines ls 2
    set xlabel "left-right"
    plot "${DATFILE}" using 1:(\$2-\$3) title "left-right" with lines ls 2
  unset multiplot
EOF
inkscape --export-png="${OUTFILE}" --export-background=white "${SVGFILE}"