Built Environment Acoustic Noise & Vibration

Built Environment Acoustic Noise & Vibration

Cambium provides acoustic and noise control design to architects, mechanical engineers, and developers for a variety of building types ranging from custom homes to international hotels, condominiums to office buildings, schools and libraries to courthouses and prisons. We know the significant importance of the indoor acoustics and its relationship to the overall built environment. Our acoustical engineers work to produce the appropriate acoustic environment for a space by designing the appropriate corresponding noise control in each of these three categories:

Architectural Noise Control

Architectural noise control addresses the acoustic separations between spaces, which primarily includes partitions, floors, and ceilings. With the upcoming changes the National Building Code (NBC) requiring separations to an Apparent Sound Transmission Class (ASTC) ratings, proper design of architectural separations is all the more critical. Where the previous requirement for separations to meet laboratory based Sound Transmission Class (STC) ratings, partition assemblies could be selected from tables with published STC ratings with no requirement to demonstrate that the intended transmission loss is actually achieved in the building construction. The common result is unintended flanking paths through other elements in the building design that render the published STC rating worthless. (Cambium’s acoustic consulting staff have become all too aware of these issues from the countless visits to unsatisfied new condominium owners.) The proposed building code changes will require these flanking paths to be considered. Cambium can provide the acoustic design to architects and builders during the design stage, to ensure that costly, post-construction fixes are avoided. Cambium also performs the Apparent Sound Transmission Class tests verify and assess the sound transmission characteristics of architectural separations, as may be required to confirm compliance with project specifications or the Building Code).

We can also test the Speech Privacy Class (SPC) to measure of the level of privacy achieved between two spaces. The test considers the sound transmission loss caused by the separation between the spaces, and the background noise level in the receiving space, to provide a single number rating to quantify the level of privacy between the two spaces. This is particularly useful for healthcare facilities and other professional offices where confidentiality is of paramount importance.

Room Acoustics

Room acoustics deals with the way sound interacts with the room, specifically, the way it is reflected or absorbed by surfaces within the room. A reverberant room provides many reflections for sound such that the sound stays in the room long after it was produced. A “dead” room provides very few reflections as surfaces will instead absorb the sound so the sound disappears shortly after it is produced.

One of the more critical aspects of room acoustic design is its effect on speech intelligibility. Our engineers will take into account the room acoustic design and consider the use of the space, the size of the space, and the selection of the appropriate absorptive (or reflective) finishes to achieve the desired acoustic environment. Cambium can test the Reverberation Time (RT60) to measure the reverberation in a room which is a very important factor in spaces where speech intelligibility is critical, such as classrooms, meeting rooms (particularly video and teleconference rooms), and auditoria.

Mechanical Noise Control

Mechanical noise control includes vibration control of equipment, and reduction of airborne noise as it passes through ducts and other pathways. Achieving the appropriate background noise is critical to proper enjoyment of the space. Cambium’s acoustic engineers will conduct tests for Noise Criteria (NC) or Room Criteria (RC) to measure the background noise, typically due to HVAC, in a room or building. We will assess the noise propagation from the mechanical equipment through various pathways, such as airborne pathways through ducts or structure-borne pathways through building components, and provide design of mechanical noise control options, such as silencer selection or equipment isolation, to meet the background noise level requirements in different types of spaces such as auditoriums, classrooms, private offices, open offices, hotel guest rooms, and residential living areas, among many others.