Can "Musicophilia" by Oliver Sacks Explain Why I'm Hearing Better?

I just picked up Musicophilia: Tales of Music and the Brain by Oliver Sacks, and it is a revelation for anyone with hearing loss and distortion of sounds that comes with it. Sacks is a physician and neurological specialist who has written extensively on previously unexplained phenomena with the brain.

His book Awakenings, about coma patients who were administered a drug and awakened, returning briefly to normal lives, only to tragically lapse back into their comas when the drugs wore off, was made into a major motion picture with Robert DeNiro and Robin Williams in 1990. Musicophilia is a big book about how the brain assimilates, creates, and otherwise processes music. Because of Sacks’s passion for understanding how the brain interacts with the physical world, it has a lot of information on how the brain works with the hearing organs to process sound and interpret what we hear. Most exciting to me, it hints at some of the reasons why I’ve experienced a marked improvement over the past several years in my ability to hear — not music, which is still gone completely for me, but to hear and understand people’s voices – even when my physical hearing tests have shown no improvement and even slight decline in hearing levels in both ears. Sacks is making me wonder whether the amazing human brain actually has the ability to correct and “cure” hearing loss to some degree, even when the physical hearing organs are damaged beyond repair.

Musicophilia describes and explains both musical hallucinations and amusia, the inability to discern tone or timbre, which makes music impossible to “hear,” listen to or enjoy. I never knew amusia had a name, only that when I lost most of my hearing five years ago I also lost my ability to hear music. While I’ve gotten better at coping with normal conversation, my amusia has been and continues to be the most devastating irreversible loss I’ve suffered. Sacks provides a case history that makes my problems with music seem small and also offers some hope. It’s about a professional musician, and composer, Jacob, who gradually loses his ability to process musical sounds correctly. But, like Beethoven, he is able to continue working by using the musical ability that his brain retains. Even better, he has “trained” his brain to correct the problem so that at times he is able to hear music properly again.

I’ve experienced something similar, in that when I concentrate really hard I can sometime properly discern a single melody played by a single instrument; often the tone leaps from one octave to another in mid-stream as my brain chooses an octave that my ears can process more or less properly, but I still can recognize the tune. I’d heard of something called “recruitment,” where the brain compensates for dead hearing cells by having adjacent cells tuned for higher or lower frequencies pick up and process the sound. So I can hear musical sounds, but they are a discordant mess because my ears hear them at all the wrong tones. But sometimes, seemingly through an effort of will or extreme concentration, I can hear the correct tones. Sacks explains this by identifying a process where the brain actually re-tunes the hearing cells to pick up and process notes at the proper frequencies:

What might seem a preposterous notion has gained support from recent work demonstrating that there are massive efferent connections (the olivocochlear bundles) going from the brain to the cochlea and thence to the outer hair cells. The outer hair cells serve, among other things, to calibrate or “tune” the inner hair cells, and they have an exclusively efferent nerve supply; they do not transmit nerve impulses to the brain, they get orders from the brain. Thus one has to see the brain and ear as forming a single functioning system, a two-way system, with the ability not only to modify the representation of sounds in the cortex but to modulate the output of the cochlea itself. The power of attention – to pick out a tiny but significant sound in our environment, to home in on a single soft voice in the ambient din of a crowded restaurant – is very remarkable and seems to depend on this ability to modulate cochlear function….

If this is true it may help explain why I’ve felt over the past several years that my hearing has improved, especially my comprehension of conversation. If the brain can command what’s left of the hearing organism to actively assimilate and discern specific kinds of musical sounds, perhaps it can also train the ears to “hear” spoken conversation in ways enabling the brain to understand speech more easily. Sacks describes how intensive work by Jacob the composer resulted in lessening of his amusia, as he worked with music and musicians all day long and actively concentrated on adjusting his tonal perceptions. I work just as hard as Jacob, but in conversational settings, because my work as a communications and media consultant requires I be the best possible listener. I thought for the longest time I was just getting better at speech reading and understanding body language and all the visual cues that help one understand what someone is trying to communicate. But perhaps my brain is also learning how to “order” my cochlea and hearing hair cells to interpret the sounds they do pick up in ways that enable my brain to comprehend speech and understand conversation better than I could when I first went deaf.

This may also hint at why a product like the Neurotone LACE speech-comprehension therapy system actually works. I have gotten through four of the 20 LACE lessons and will have a report on the results in a future post.