Acoustics within a building envelope requires consideration of interior geometry, suitable surface treatments, wall constructions, and control of noise from building systems. Architectural acoustics is our most common type of job category, with residential and multi-dwelling noise control studies our most common type of sub-category.  We are usually retained by an owner, developer or architect to take care of how a building will "sound" and to ensure that appropriate privacy, quality and speech intelligibility parameters will be met in the design stage.  However, we are also often retained after construction to correct glaring acoustical problems that could have been dealt with during the design phase (can you spot the acoustical problem in the wall cross-section below?).