LYNN NEARY, host:
We all like music. Who doesn't? But what would happen if the songs we hear in our heads, what if they stayed and stayed?
NPR's science correspondent Robert Krulwich has the story.
ROBERT KRULWICH: We will begin with the patient, says Dr. Oliver Sacks, neurologist and author.
Dr. OLIVER SACKS (Neurologist): This is an intelligent, very deaf woman.
KRULWICH: Who has a hearing aid now, a cochlear implant, but back when she was in her 60s...
CHERYL C: I had been steadily losing my hearing.
KRULWICH: And then, about fiver years ago, Cheryl C, as Dr. Sacks calls her in his new book, "Musicophilia," she was at home with her husband in bed, reading.
CHERYL C: And all of the sudden I heard horrific noises.
Dr. SACKS: She heard engines going to and fro.
CHERYL C: Trolley cars.
Dr. SACKS: There were sirens, there were voices, there were bells, there was screaming, there was clanging.
CHERYL C: Cymbals.
KRULWICH: And all of a sudden, just pow?
CHERYL C: Just all of the sudden.
KRULWICH: Trolley cars?
CHERLY C.: And I turned to my husband, who was in the...
Unidentified Man (Husband): Yeah, I was there. I mean she jumped up and said I've got these noises.
CHERYL C: I ran out of the bedroom.
Unidentified Man: Such a strange thing happening.
Dr. SACKS: She rushed to the window, expecting to see a fire engine, and there was nothing there. There was nothing.
CHERYL C: And I suddenly realized that these horrendous noises were in my head.
Dr. SACKS: She was having a hallucination, a sort of monstrous hallucination.
KRULWICH: And then after maybe 20 minutes of clanging and banging, just as suddenly...
Dr. SACKS: The noise was abruptly replaced by the sound of music.
CHERYL C: "Michael Row Your Boat Ashore."
KRULWICH: And that song was followed by a slew of other songs.
CHERYL C: Hymns, spirituals, patriotic songs, things (unintelligible)...
Dr. SACKS: And from that point on her hallucinosis took the exclusive form of music.
CHERYL C: Playing intensively. I can't stop it.
KRULWICH: Weren't you worried that you had become a crazy person?
CHERYL C: Yeah, I thought I might be going nuts.
(Soundbite of laughter)
CHERYL C: And that bothered me.
KRULWICH: So she went to see Dr. Sacks, who examined her and did all kinds of tests.
Dr. SACKS: She first wondered if she was going crazy. This was like hearing voices.
CHERYL C: And he assured me that, you know, I wasn't.
KRULWICH: Whatever is wrong with you has a physical explanation, he thought.
CHERYL C: It was neurological. There was something causing it.
KRULWICH: But what was causing it? Dr. Sacks told Cheryl that because her hearing was so compromised...
Dr. SACKS: She was profoundly deaf.
KRULWICH: Hardly any sounds were coming into her brain, so the cells in her brain dedicated to hearing - those neurons were under-stimulated.
Dr. SACKS: If the hearing parts of the brain, they're not getting their normal input, start to produce a factitious, hallucinatory output of their own.
KRULWICH: And therefore the reason there is music in Cheryl's head is she got so deaf, the hearing cells in her brain, desperate for exercise, started making stuff up. That's kind of what he told her.
CHERYL C: Dr. Sacks explained to me that my brain just decided to make some music - and so I'd hear something. That is really what it is.
KRULWICH: Oh, come on. I thought that can't be. But Dr. Sacks says this happens all the time.
Dr. SACKS: This is not uncommon. This is not psychotic. This is often associated with deafness.
KRULWICH: Or even with boredom. People stuck in faraway places.
Dr. SACKS: Where there is a vast silence. They may start to hear things.
KRULWICH: I said, what are you talking about? He said, okay, let's pause. Let's stop the story of Cheryl just for a moment because to understand Cheryl it will help if you met Michael Sandou, a New York City graduate student. I said why, who's Michael Sandou? And he said, well, just ask him to tell you the story that he told me. So I did.
Mr. MICHAEL SANDOU (Graduate Student): I was - it was a story about being extremely bored, really, which is why I was - almost felt silly coming down here and telling you the story.
KRULWICH: But to speed things up, Michael was invited by a school friend to sail on a boat from the Caribbean to Connecticut.
Mr. SANDOU: And I didn't know anything about sailing and just thought it would be exciting to go.
(Soundbite of laughter)
Mr. SANDOU: And I found it the opposite.
(Soundbite of laughter)
Mr. SANDOU: It was so boring. There is no wind.
KRULWICH: So he spent more than two weeks mostly staring at totally flat water.
Mr. SANDOU: In a few days I had read every book I brought, and it just went on and on and on.
KRULWICH: Until finally one afternoon, sitting on his birth listening to a refrigerator hum, he heard...
Mr. SANDOU: Heavy metal guitar solos.
(Soundbite of laughter)
KRULWICH: There's no radio, no CD, no music playing anywhere, and yet...
Mr. SANDOU: In my head, it's... (makes guitar sounds) ...forever. And I don't like heavy metal. I mean punk, yes. Metal, no.
KRULWICH: Had this ever happened to you before that you remember?
Mr. SANDOU: No.
KRULWICH: But the guitar kept playing and playing and then later he had a second hallucination.
Mr. SANDOU: Highland bagpipe, and I don't know anything about the bagpipe.
KRULWICH: But Michael's brain produced those bagpipes, just as Cheryl's brain had produced "Michael Row Your Boat Ashore."
Brains, even healthy brains, do this when there's nothing real coming in, especially as with Cheryl when you're deaf.
Dr. SACKS: Something like 2 percent of people with severe deafness can get musical hallucinations. And although it may be very annoying or intrusive, things tend to die down and one tends to get used to it.
CHERYL C: I have learned to live with it.
KRULWICH: But that doesn't mean she likes living with it. It never stopped.
CHERYL C: I would wake up in the morning and think, what, what's the tune de jour, what are we going to be hearing today? And there was always one there.
KRULWICH: And that's when she thought about cochlear implants. She heard about an ear doctor.
CHERYL C: He'd had a patient, he had told us about Sacks, who had musical hallucinations, received a cochlear implant, and her hallucinations disappeared. So...
KRULWICH: That makes sense, right? I mean, because if this is idle neurons wanting to do something, if you bring the world back into your head, presumably those neurons would have something to do.
CHERYL C: So I wanted to do it.
KRULWICH: And so she did it. She took a chance. She had the operation. She got the implant. She woke from the operation and...
CHERYL C: I heard the music. It was inside me.
KRULWICH: Oh, still there. Her brain cells for some reason continued to produce their own music, plus she can now hear real music coming through the implant. And the curious thing is the implants have such a narrow range, real music feels flat to Cheryl.
CHERYL C: It sounds tinny. I really don't hear a musical intervals the way you would like to.
KRULWICH: But the music that she hallucinates...
CHERYL C: Yes, it's great. Everything hits the right note. It's fine.
KRULWICH: So for Cheryl, when I sing...
(Singing) Michael row...
(Speaking) ...she hears...
(Singing, tinny) ...Michael row your boat ashore.
(Speaking) Real sounds sound terrible. But when Cheryl's brain hallucinates "Michael Row Your Boat Ashore"?
(Soundbite of music)
KRULWICH: ...oddly...
CHERYL C: It sounds the way music should sound.
KRULWICH: Isn't that weird? So...
CHERYL C: The whole thing is a little weird. But I try not to think about it that way.
KRULWICH: Robert Krulwich, NPR News, New York.
(Soundbite of music)
NEARY: You can hear more stories by Robert Krulwich in his podcast, Krulwich on Science at npr.org/podcast.