As a cost-saving measure in some buildings, interior walls are instead stopped at the height of a suspended, modular acoustic ceiling.
They do not extend full-height up to the structural floor slab or roof.
This practice not only saves on the construction cost of the walls, but also creates a continuous open space above the suspended ceiling that can be used as a return-air plenum.
Specifying a plenum to return air can save money,
compared with the cost of adding rigid metal return-air ductwork above the ceiling.
This design approach typically does not comply with minimum sound-isolation performance requirements in standards, guidelines, and rating systems because sound can transmit at higher levels
through the lightweight acoustic ceiling and over
the partial-height wall. Some designers and building owners still elect to use this approach for the cost savings.
Eliminating the need to choose between a design approach that works acoustically and one that
works financially was one of the motivations for
the Optimized Acoustics Research Program, an ongoing, multi-year,
multi-organization investigation into cost-effective means of designing and constructing interior architecture that complies
with the acoustic requirements in industry standards, guidelines, and building rating systems.
The initiative began in 2014, and progress
updates of the findings, such as this article, have been presented at and published in
the proceedings of InterNoise, NoiseCon, and Acoustics Week Canada, as well as published in Sound & Vibration and Canadian Acoustics.)
An early phase of this initiative investigated the effects of noise flanking paths, or ‘leaks,’ through penetrations in liechtenstein number the ceiling system
when the demising walls stop at the height of the ceiling instead of extending full-height.
Suspended, modular ceiling systems
typically have recessed light fixtures, open return-air grilles, supply air diffusers, and other miscellaneous penetrations for sprinkler heads,
loudspeakers, security/surveillance devices, and Wi-Fi devices. in the ceiling system create noise flanking paths,
through which noise transmits more easily between rooms.