The arena was built with the knowledge of Greeks to keep the sound within, so that every lone whisper could be heard, to a reasonable distance - the arena was huge, after all.
Problem was, the crowd was bewildered after the kill, so he didn't bothered outvoicing them.

Welalurd turned to the Carthaginian nobles that surrounded him at his royal seat.

"Ever-hungry Baal showed us his approval of our Suffet of war. Our upcoming campaign promises much. Long have our harbours been kept under chain, long have our ships been on dry land... With iron will and wooden ships, we will restore deserved Carthage's fame! Our home will again be recognized as The City in every corner of the Mediterranean!"

Welalurd raised his goblet of wine.