# Why do octaves sound the same?

**Why do we hear notes an octave apart as the same note?**

An octave is a doubling of frequency, and many animals respond to it. Part of the story is in the harmonic series and the ear, and part may be learned.

Connects to:
- [The octave](https://mapideas.org/i/mu_octave)
- [The cochlea](https://mapideas.org/i/mu_cochlea)
- [The harmonic series](https://mapideas.org/i/mu_harmonics)

Source: https://mapideas.org/i/q_mu_octave · open on the map: https://mapideas.org/#q_mu_octave