An acoustic sleeper for sound suppression in a floor assembly may be formed as a solid sleeper body made entirely from a resilient acoustic isolating material. The sleeper body has a thickness, a width, a length, a generally rectangular cross-section and first and second sides. The sleeper body first side includes a first side area and a first sleeper load-bearing surface for contacting a first floor assembly structure, the first sleeper load-bearing surface having a first load-bearing surface area equal to or less than the first side area. The sleeper body second side has a pair of solid sleeper feet extending therefrom. The sleeper feet collectively provide a second sleeper load-bearing surface for contacting a second floor assembly structure. The second sleeper load-bearing surface has a second load-bearing surface area that is less than the first side area by at least a factor of three.