Sound and Privacy
Acoustic Considerations for Residential Buildings
09 October 2020
Residential buildings must address several acoustical concerns: exterior noise control, transmission into the residence, background noise/vibration, and noisiness within rooms. When attempting to mitigate these, many factors must be considered as well. This might include the factors of human perception and sensitivity to acoustic privacy, isolation from both exterior and interior noises, equipment sound levels and interior room acoustics. It is important to understand these factors to best address them in residential buildings and projects.
Factors in Human Perception and Sensitivity
There are four factors that impact people's sense of sound privacy. To achieve the acoustical privacy that occupants are seeking, all of these factors need to be considered and balanced to arrive at a successful outcome.
- The loudness or intensity of the sound plays a significant role in our perception of the intrusive sound; loud sound or high intensity activities can intrude more easily on neighboring spaces. However, this factor is often something that is not always controlled by the developer or designer.
- The isolation of the construction is most significantly influence by designers and building code requirements, for multi-family projects. This is where projects spend a majority of their effort, and where all of these factors should be focused for achieving the desired privacy.
- Background sound level where the listener is located. This is an important factor as quieter settings can allow more intrusive sounds to be heard, meaning moderate background sound levels can be helpful to one's privacy. This is the basis for why white noise machines can be effective.
- Personal sensitivity is unique to individuals and based on several personal and unique factors making it difficult to predict or change.
Airborne and Impact Sound Isolation
Both exterior and interior sound isolation need to be considered with residential projects. When isolating exterior noises, thermal insulation and air sealing are often very beneficial. Air sealing helps stop sounds travelling through the air; porous insulations within the exterior wall cavities are effective sound absorbers. In areas with high noise exposure, more massive constructions increase the wall's ability to block noise and separated framing or glazing are also helpful to isolate structural transmission paths. It is important to use a combination of these mitigation measures to strike the right balance.
Interior isolation can be accomplished through the use of sealants, mass (extra layers of drywall), porous insulations, separated constructions, laminated drywall, and in floors impact-isolating underlayments for hard flooring.
Equipment Sound Levels
Building equipment, such as HVAC systems, appliances and garage doors or elevators may contribute to the noise in a residential building. Conceptual noise control for these noises might include measures like locating equipment away from sensitive areas like bedrooms or living rooms. It could also include selecting quieter equipment and isolating equipment from the structure, if possible. In modern residences, it may be easier to accomplish as there is the possibility for less or quieter equipment.
The selection of finishes within the house can help control the buildup of noise for occupants. For example, hard surfaces reflect sound and large rooms can create excess acoustical liveliness that can be considered noisy. Sound-absorbing products can help reduce this effect and control noisiness. A wide range of sound absorbing products have the appearance of more traditional finishes and provide excellent sound absorption. In newer homes, open concepts can result in rooms with taller ceilings and large volumes, allowing more reverberation and fewer barriers and a more intense feeling of noisiness.
Acoustics plays an important role in the overall comfort of a home and, as such, must be considered in building projects. There is a wealth of acoustical products that can solve the range of acoustical issues that residences face provided they are used appropriately for solving the issues. Get more insights into this topic by downloading our on-demand webinar.
Department Manager, Building Science Solutions
Jeff Fullerton has more than 20 years of experience providing acoustical consulting guidance to clients. His past projects include mixed use facilities, entertainment venues, corporate and commercial buildings, single and multi-family residences, higher education buildings, government facilities, transportation terminals, healthcare facilities, and industrial plants. He holds degrees in mechanical engineering, holds several related professional certifications, and is a Fellow with the Institute for Noise Control Engineering.