The low-frequency limit of proposed ratings for quantifying low-frequency impact insulation

Intensive Resolution Measurement With the Samdis Multi-Aspect Sas

“…It is obviously very tempting to try to implement methods for measuring resolution without having to deploy specific targets at sea. These methods 5,7 often rely on a statistical approach where the image is assumed to contain natural point-like objects. These methods seems to be interesting to give an indication of the image quality.…”

Design of Floor-Ceiling Assemblies Using Dual Ratings of Impact Noise Insulation

“…For example, we have determined that an 8-inch (200 mm) concrete slab is 5 LIIC points better on average than a 6-inch (150 mm) slab. In contrast, adding a ceiling to a concrete slab, while it greatly improves the impact insulation at most frequencies, has no measurable effect on the LIIC [18]. Different brands of resilient channel can account for 7 LIIC points difference between wood truss assemblies [19].…”

“…where Δ𝐿 𝑛 is the reduction in impact sound level at frequency f, 𝑓 0 is the resonance frequency of the floor covering, and K is a constant (often taken to be 40). This behavior is well known for concrete structures and included in standard calculation methods [13], but this can also be shown [14] to accurately describe the observed behavior of lightweight joist-framed floor-ceiling assemblies.…”

“…It may be possible to use single ratings for subsets of the data. For example, the authors previously examined typical German floor assemblies [14] and found that they mostly had very good high-frequency impact insulation. For these assemblies, the high-frequency insulation is good enough and only the low-frequency issue remains to be solved, and the problem has been reduced to a single dimension.…”