If something deadens a feeling or a sound, it makes it less strong or loud. He needs morphine to deaden the pain in his chest. to make a feeling or sound less strong
convert (metallic mercury) into a grey powder consisting of minute globules, as by shaking with chalk or fatty oil make less lively, intense, or vigorous; impair in vigor, force, activity, or sensation; "Terror blunted her feelings"; "deaden a sound"
To make as dead; to impair in vigor, force, activity, or sensation; to lessen the force or acuteness of; to blunt; as, to deaden the natural powers or feelings; to deaden a sound