I was walking with wolves. The alpha was patrolling the perimeter of the pack's territory, sniffing things and marking the snow with the scent glands between his toes. As we circled back we howled a few times for the rest of the pack to join us
there were two tones in the "oo" part of the awoo, first high, then low. And not really a "w" sound
aOOOOOuuuuuu
^-- aka "spell for summoning wolves"