On page 276 of The Ends to Power, H.R. Haldeman (with Joseph DiMona) says the following about President Richard Nixon’s valet, Manolo Sanchez, and how his serving Nixon coffee made a lot of racket on Nixon’s tapes:
“Manolo is well known—-and damned—-by all listeners to the tapes as
the creator of the thunderous, ear-splitting crashes which usually
occurred as the sound was turned up in order to hear a low pitched
voice. The thunder was caused by Manolo delicately placing a cup of
coffee on Nixon’s desk in which the microphones were installed.”
I laughed out loud when I read that!