Abstract: A wall for attenuating highway noise and the like comprises spaced apart posts set generally perpendicular to the ground slope, and panel sections secured therebetween. Each post includes a T-channel member with an elongated locking plate removably secured to the edge of the web of the T-channel and disposed normal thereto. Between the locking plate and each branch of the T-channel a panel jamb is resiliently secure, and one end of a pre-assembled panel is joined to each jamb. In one embodiment the panels are constructed of double-walled courses supported by horizontal joists which are joined to the jamb. In another embodiment the panels are formed of courses of parallel right-angle members resiliently locked into vertically spaced slotted bars, with acoustic insulation secured between the right-angle members.