soundlessness

From soundless +‎ -ness.

soundlessness (uncountable)

1. The state or condition of being soundless.
   • 1913 January–May, Edgar Rice Burroughs, “The Gods of Mars”, in The All-Story, New York, N.Y.: Frank A. Munsey Co., →OCLC; republished as chapter XII, in The Gods of Mars, Chicago, Ill.: A[lexander] C[aldwell] McClurg & Co., September 1918, →OCLC, page 186:

     A stealthy glance below revealed no guard in sight, and so with the quickness and the soundlessness of cats we dropped together into the main cabin of the submarine.

• (state of soundless): noiselessness, silence

• sound
• soundless
• soundlessly