A sound-baffling arrangement for use in conjunction with an air-handling unit. One or more sound baffle columns are mounted for rolling or sliding movement within the interior of the air handling unit housing. Each baffle column may be selectively moved between a use position proximate to the fan assemblies, and a non-use position more distal from the fan assemblies. The movable sound baffles permit the air-handling unit to be fabricated to fit within a smaller housing, and thus to have a smaller, more economical footprint.