Octave | |

When
two pitched sounds are in a relationship such that the frequency of one
is twice that of the other (2:1), the interval
is said to be an octave.
a doubling (2X) or halving (/2) of a frequency |

Paradoxically, two sounds in an octave relationship sound as if they are the same pitch or unity (1:1) but with the doubled one sounding "higher." The same phenomena occurs with successive doublings of frequency as in 4:1, 8:1, etc. |

octave
sine tone 220 hz and 440hz |

pinetrees
normal |
snake
up one octave |
snake
down one ocatve |