How a cochlear implant lets the brain hear
A hearing aid makes sound louder, but a cochlear implant takes a completely different approach: it bypasses the damaged hair cells and fires electrical pulses straight into the fibers of the auditory nerve. We take one apart and follow a voice from the microphone, into digital code, through the skin by radio and into the cochlea, where 12 to 22 electrodes stand in for about 3,500 inner hair cells. It doesn't restore natural hearing. It gives the brain a new kind of input, and the brain learns to hear it as sound.
- 0:00 Silence, hearing aid, implant
- 0:21 Exploded implant
- 0:37 Sound becomes code
- 0:46 Through the skin
- 0:55 Inside the cochlea
- 1:13 Healthy ear, coiled
- 1:34 Switch-on day
- 1:43 The brain learns
- 1:58 What it gives