How does Odysseus' men protect him from the song of the sirens?

Cicre warned Odysseus not to listen to the songs of the sirens, but he was detirmined to! So he had his crew tie him to the mast of his ship as he rowed past. He ordered them to all fill their ears with wax to block out the song. He also told then that once he was tied to the mast they were not allowed to let him down, no matter how hard he protested.

When they sailed past Odysseus heard the song and desperatley wanted to go to the island, but his men, as ordered, did not let him down, only when they were past the island did they let him down.