All 3 Uses

audible
in
Frankenstein - 1831 version
(Auto-generated)

Sometimes she struggled with her tears, but when she was desired to plead, she collected her powers and spoke in an audible although variable voice.†
p. 84.7 *

audible = capable of being heard
He played a sweet mournful air which I perceived drew tears from the eyes of his amiable companion, of which the old man took no notice, until she sobbed audibly; he then pronounced a few sounds, and the fair creature, leaving her work, knelt at his feet.†
p. 110.9

audibly = in a manner that can be heard
The laughter died away, when a well-known and abhorred voice, apparently close to my ear, addressed me in an audible whisper, "I am satisfied, miserable wretch!†
p. 206.8

audible = capable of being heard

Definitions:

(1) (audible as in: barely audible)
capable of being heard
(2) (meaning too rare to warrant focus)
In football, the term has come to include an instruction shouted from the line of scrimmage.

Recently, the word is also being used to indicate sounds that could be played on a phone or computer; for example "audibles include creative hellos that can be downloaded."