Direct Opposites:
* Speaker: If "audience" refers to the listeners, the speaker is the opposite.
* Performer: If "audience" refers to the viewers, the performer is the opposite.
Indirect Opposites:
* Silence: If "audience" implies noise or reaction, silence is the opposite.
* Isolation: If "audience" implies a group, isolation is the opposite.
* Secrecy: If "audience" implies public presentation, secrecy is the opposite.
Ultimately, the best antonym will depend on the specific situation and the intended meaning.