In the science of language, most words have root sounds that tend to have a group meaning attached to them.
I think that Bob's message was attempting to make it clear that if he does not have and audient or audience that is willing to utilize their auditory skills in order to receive the audio, then the communicator must attempt to rephrase the communication in the manner that will more entertain a more complete auditory audio understanding of the audient or audience.
Keep in mind however that the above opinion is solely my own, and that the result of the communication can be deemed by an audient to be the fault of my communication of the thought rather than the fault of their auditory skills.
Then again, in sheer audacity, others may blame the other one.
(audacity)... One entry found for audacity. Main Entry: au·dac·i·ty Pronunciation: o-'da-s&-tE Function: noun Inflected Form(s): plural -ties Etymology: Middle English audacite, from Latin audac-, audax Date: 15th century 1 : the quality or state of being audacious : as a : intrepid boldness b : bold or arrogant disregard of normal restraints 2 : an audacious act -- usually used in plural synonym see TEMERITY