#!/bin/sh

for i in $*
do
   ch_wave -otype raw -ostype ascii $i |
   awk 'BEGIN { z=0; }
        { if ($1 == "0")
          {
             z = z + 1;
          }
          if (z > 2 )
          {
             printf("%d\n",(rand()*10)-5);
             z-=1;
          }
          else
          {
             printf("%d\n",$1);
             if ($1 != "0")
                z = 0;
          }}' |
   ch_wave -itype raw -istype ascii -f 16000 -otype riff -o $i
done