If you control more than one Emcee, each ability triggers separately. You have to announce the creature's entrance each time. Okay, you can just stay standing if you want.

Emcee's ability will trigger whenever a creature enters the battlefield under an opponent's control. You choose whether you announce its arrival or not.

You may add in nicknames for the creatures you announce, but you must also get the creature's actual name in there to count. For example, "Gary, the Gray Merchant of Asphodel" is fine, but simply "Gary" wouldn't work.

If you are unable to use a deep, booming voice, you are free to make accommodations in the spirit of Emcee. Sign overly dramatically, for example.