Patent ID: 8316986

Claim:
A method of reducing sound transmission levels in a building comprising multiple rooms separated by walls, at least some of the rooms having respective ceiling openings in airflow communication with a common plenum space, the method comprising: providing a substantially planar sound absorbing member made of a flexible material in a length longer than a ceiling opening for a first room; positioning a first end of the sound absorbing member at a first end of the ceiling opening; forming the substantially planar sound absorbing member by hand into an arch shape or a peak shape and positioning a second end of the sound absorbing member at a second end of the ceiling opening to self-supportingly retain the arch shape or the peak shape, the sound absorbing member at least partially defining, together with a perimeter of the ceiling opening, a pair of side openings; and configuring a sound transmission path to have at least one change of direction greater than 45 degrees between the ceiling opening and at least one of the pair of side openings.