Sailors who’ve crossed oceans solo have reported—both in books and in personal conversations—the prevalence of auditory hallucinations. In particular, hearing voices.
Well I can now count myself among those who hear voices at sea. (And sometimes sounds from my phone!) Once in a while I can make out a distinct word or phrase; but for the most part it sounds like indistinct background conversation.
However, I’d personally not categorize this phenomenon as hallucination. You see, there are dozens of sounds occurring continuously: the wind blowing; waves crashing on the hull; seawater gurgling up into the cockpit drain pipes; squeaks and squeals of the self-steering system; groans and shudders as mechanical parts of the boat alternately take and release load forces; and so on.
Many of these sounds contain strong components in exactly the frequency range to which the human ear is most attuned: the human voice. I suspect that the brain’s auditory and language systems are wired and/or conditioned to look for (and find!) patterns in this spectrum.
If this is the case, then it’s not surprising that any properly-composed cacophony would sound like voices. Like listening expectantly to static on the radio, and being almost certain you can make out a voice just behind the noise…
Of course, when I hear what sounds like whistling, excited shouting, or a horn (I heard all three with regularity)—basically anything that could be another vessel trying to get my attention—I still feel compelled to check, every time, just in case.
But if I start to see people or begin talking to Wilson, I’ll probably keep it to myself.