Talking loud, saying nothing

Herbert Smith has long been trying to get away from its image as a litigation firm, offering many other talents. Including, it now seems, sound engineering.
At its recent Paris conference, a group of somewhat inebriated partners rerigged the microphone equipment in the lecture hall so that, instead of amplifying the words of the speaker, it would pick up the conversations of those seated around the room. Purely, Tulkinghorn assumes, to gain the inside track on what partners were really talking about.
Unfortunately for them, after said partners returned to their hotel, the real sound engineers stepped in and realigned the system to spoil the prank.