#!/usr/bin/perl -w
use strict;

my %hash = (
    son    => { year => 2006, name => 'Paul', },
    father => { year => 1981, name => 'Ryan', },
    mother => { year => 1978, name => 'Bose', },

);

print sprintf(
    "%s: %s",
    'Person' . $/,
    do {  ## <== note here
        my $order;
        for ( sort keys %hash ) {
            $order .= join ' | ' => $_, %{ $hash{$_} }, $/;
        }
        $order;
      }
);