(Linux) sound with Perl and a few lines of PDL

pdl_sound.pl

use PDL;
my $freq = 440;
my $rate = 8000; # default for aplay

my $samples   = pdl[0..$rate-1];

open (my $aplay,'|-','aplay');

my $raw_sound = byte(zeroes($rate));
my $amplitude = 64;
for (1..5) {
    $raw_sound += byte($amplitude*(1+sin($samples*$_*$freq*6.28/$rate)));
    $amplitude /= 2;
    print $aplay $raw_sound->get_dataref->$*;
}

close $aplay;