Biological humans can most often hear about 10 octaves, from 20 Hz to somewhere in the 10–20 kHz range, although slower pressure oscillations can affect them. Analogously, though they seem to be conscious from birth, they usually cannot remember much that happened before the age of 2 years or so. We could say, then, that they can perceive 6 octaves of their lifetime.
The first octave is from 2 years to 4 years. In the first octave, they most often learn to walk, talk, and theorize about others' minds.
The second octave is from 4 years to 8 years.
The third octave is from 8 years to 16 years.
The fourth octave is from 16 years to 32 years. Many humans cease to learn when they enter this octave, instead busying themselves with trivialities. During this octave they pass from being enslaved by their instincts to being enslaved by their delusions and their habits. Their brains and the rest of their bodies continue to grow, and their peak physical and mental capacities are usually reached during this time.
The fifth octave is from 32 years to 64 years. This is the octave of greatest exploitation, in which humans most often exploit their previously-gained capabilities, which remain more or less consistent during this time. A few continue to develop during this time. Nearly all survive to the end of it.
The sixth octave is from 64 years to 128 years, although quite possibly no biological human has yet lived beyond 122 years. This corresponds roughly to the human idea of “old age”; their physical and mental capacities decline and their risk of death rises superexponentially. During this octave, many humans regret having wasted their previous opportunities, and many blame others for this and become bitter.