Cage makes a point when he formulates one of the fundamental lessons of his infamous composition 4'33" (a work he claimed was inspired, not coincidentally, by Rauschenberg’s White Paintings): there is no such thing as silence. Take away one sound, and there are always others— fainter, or more nuanced and neutral, or simply so regular that they have merged into the background.
Eliminate those fainter sounds and you only open onto yet others in turn: the barely perceptible shimmer of electrical circuits; the ambient hums that inhabit rooms even before we do; the respiration of space.
Continue all the way to the threshold of hearing itself. The tympanic membrane and the organ of Corti resonate with amplitudes approaching the diameter of a hydrogen atom; if the human ear were more sensitive by even a degree we would hear the crash of atoms colliding in their erratic Brownian sweeps, the constant din of fluctuations in molecular density.
But even if we could listen in a vacuum, free from the imperceptible white noise of molecular space, we would still be awash in sound.
As long as we are alive we never escape the systolic waves of the hematic ocean tiding in the nautilus turns of the ear.