The sounds from the above scripts were not working when I actually tried to use them, so I wrote it again using Audio::Data. This script has worked great so far on real telephone lines and other devices. This save as an au file, but if you need a wav you can use something like ffmpeg to convert it.

#!/usr/bin/perl
use strict;
use Audio::Data;

my(@tones) = qw(1 2 3 4 5 6 7 8 9 0 * #);

my %lut =
(
 '1'=>[697,1209], '2'=>[697,1336], '3'=>[697,1477],
 '4'=>[770,1209], '5'=>[770,1336], '6'=>[770,1477],
 '7'=>[852,1209], '8'=>[852,1336], '9'=>[852,1477],
 '*'=>[941,1209], '0'=>[941,1336], '#'=>[941,1477] 
);
  
my $rate = 44000;

my $audio1 = Audio::Data->new(rate => $rate);
my $audio2 = $audio1->clone();

foreach my $tone (@tones)
  {
  $audio1->tone(${$lut{$tone}}[0],.3,.8);
  $audio1->silence(.05);
  $audio2->tone(${$lut{$tone}}[1],.3,.8);
  $audio2->silence(.05);
  }

my $final = $audio1 + $audio2;
open(my $fh, '>dtmf'.join('',@tones).'.wav');
binmode $fh;
$final->Save($fh);
close($fh);
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