If you listen to both the male and female versions of the previous examples, you will notice that the sequence of notes is relatively the same. The male voice example is simply a lower version of the female voice example. These male and female versions are one octave apart.
The following example demonstrates all the natural notes from A in the bottom space of the bass staff to A on the first ledger line above the treble staff. This covers a range of three octaves. An octave is the range of eight notes between and including any two notes of the same name. Every time you come to a new A note a new octave begins. The same applies to all the other notes. For example, Middle C is one octave above the C in the second bottom space of the bass staff; the F in the bottom space of the treble staff is one octave below the F on the top line of the treble staff, etc.