This episode is the first of our six-part series, Making Sense, and it aims to reframe the relationship we have with our sense of hearing.
In the first half, we discuss the basic question: What are we actually hearing, when we’re hearing? It turns out that hearing is largely constructed in our brain. For example, if we were actually hearing everything in the world, when we hear a voice in a room, we would hear an absurd amount of overlapping echoes coming from the sound waves bouncing off every wall. Instead, our brain edits out these echoes, only presenting us with the source of the sound.
The mechanics of this brain editing is revealed when we look at audio illusions. Psychologist Diana Deutsch tells the story of how she discovered a series of illusions, which demonstrate that what we hear often differs from the real world, how much of what we are hearing is actually constructed by our brain.
But this brain editing isn’t simply a parlor trick. In the second half of the episode, we show that brain editing can have significant consequences, allowing people who have lost their hearing to regain a form of it. Michael Chorost tells the story of how he lost his hearing, and how he was able to listen to music again using a cochlear implant, which bypasses the ear and sends an audio signal directly to the brain. Michael details how he trained his brain to associate certain signals with specific sounds, and how he was ultimately able to hear his favorite piece, Bolero, again.
In both of these segments, we wanted to use the medium of audio to allow the listener to directly feel the limitations and enormous potential of our sense of hearing. In the first half, we played Diana’s illusions before describing how they work, allowing listeners to have the same feeling Diana did when she discovered them, to actually feel their sense of hearing deceiving them. In the second half, we used sound from a real cochlear implant sound generator (shared with us by an audiologist) to show how the sound created by a cochlear implant differs greatly from sound that comes from our ears. That being said, we also showed how, with training, the sound from an implant can be made to improve, relying on the magic of brain editing to provide a fuller, detailed representation of sound.