The cochlea splits sound into narrowband signals that the brain processes individually

Evidence

The processing of sound begins in the cochlea, where the sound is divided into narrowband time-domain signals, which are then processed in the brain more or less individually. When a spectrally broad sound is presented to a subject, a relevant question is what is the frequency resolution of the neural presentation? — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 973