Avalon Bay owns or holds an interest in approximately 150 apartment communities in ten states and the District of Columbia, operating under the slogan, “Enhancing the lives of our residents”. Cerami & Associates was hired to assist in doing just that, by providing our acoustical consulting services for their facilities throughout the tri-state area, and ensuring that the Avalon Bay Communities residents are living in acoustically sound environments.
We conducted Impact Insulation Class (IIC) and Noise Isolation Class (NIC) tests on the floor and ceiling constructions at each site and offered advice on floor coverings to achieve the standards of speech privacy, vibration isolation, and airborne sound transmissions we had developed through both our past experience and site surveys.
The NIC rating represents the ability of a particular building structure to reduce airborne sound transmission. The test consists of generating a broadband pink noise within a source space, and measuring the sound levels in both the source and receiver spaces. The difference in sound levels between the two rooms represents the noise reduction across the separation and is the basis for the NIC rating.
To test for IIC, we place a standardized tapping machine made of mechanical hammers at the center of the subject’s floor area and measure noise levels in the space directly below. Those measurements form the baseline for IIC ratings. After adjusting the measured levels for background noise level and room absorption, we repeat the process several times, with different floor coverings.