A modular wall with acoustic properties including one or more wall modules arranged in a desired configuration, and methods of forming the same. The wall module includes a frame configured to receive a plurality of wall elements, and a plurality of wall elements attached to the frame. An acoustic substrate is secured to the frame by a ladder or ladder frame including horizontal support members coordinated between retaining members configured for attachment to the frame or elements thereof. The frame and ladder or ladder frame can be used to sandwich one or more acoustic substrates therebetween. Exterior wall, finishing, and trim elements can be attached to the horizontal support members, frame or frame elements, and other wall elements for structural and/or aesthetic purposes.