Abstract: A structural block useful in constructing a wall for absorbing sound. The structural block includes a pair of internal cavities which are separated by a center wall. A pair of angled front walls are positioned along the front surface of the structural block. The block further includes a pair of acoustical openings. The first acoustical opening is located in the center wall, while the second acoustical opening is located in one of the end walls. Each of the pair of acoustical openings provides a path for sound to travel from the exterior of the structural block into the pair of internal cavities, where the sound is dampened. Preferably, the structural block contains a pair of retaining grooves on each of the end walls and on each side of the side wall to retain a sound attenuator which can be positioned within each of the internal cavities.