How do you give all your characters their own distinct voice?

These articles have a more distinct personal voice than an editorial.

From inside a female voice - distinct and clear - answered.

First recognized as a species due to its distinct voice, it was only described in 1997.

Her books are often characterized as having distinct female voices.

The same distinct voice ordered him to turn right, at the double.

They were the first distinct and individual voices he had heard since coming into this new land.

If there is no thesis, the book has a clear point of view, a distinct voice.

He said three foul words in a low, distinct voice.

He could produce many distinct voices from one breath to the next.