ASTM C634:13(R2021) pdf free download – Standard Terminology Relating to Building and Environmental Acoustics.
In analogy with alternating voltage its magnitude can be expressed in sescral ways. such as instantaneous sound pressure or peak sound pressure, hut the unqLlalihed term means root-mean-square sound pressure. In air, the static pressure is barometric pressure.
sound pressure level, n—of airborne md, ten limes the common logarithm of the ratio of the square of the sound pressure under consideration to the square of the standard reference pressure of 20 tPa. The quantity so obtained is expressed in decibels.
Disctxsios—The pressures are squared because pressure squared. rather than pressure. is prnportmnal to power or coergy.
sound transmission class, n—a single- number rating calculated in accordance with Classihcation F.4 13 using values of sound transmission loss. It provides an estimate of the performance of a partition in certain common sound insulation problems.
n—of a partition. in a specified frequency band, the fraction of the airborne sound power incident on the partition that is transmitted by the partition and radiated on the other side.
Discissios—Unless qualified, the term denotes the saluc obtained when the specimen is exposed to a diffuse sound field ax approximated. for example. in reverberation moms meeting the requirements of Test Method E90.
sound transmission loss, n—of a partition, in a specified frequency hand, ten limes the common logarithm of the ratio of the airborne sound power incident on the partition to the sound power transmitted by the partition and radiated on the other side. The quantity so obtained is expressed in decibels.
Dixcussios—Unless qualified, the leon denotcs the sound loss obtained when the specimen is exposed to a diffuse sound held ax ipproxirnated. for example. in reverberation roms meeting the requirements of Test Method EM).
source room, n—in urchum’ctural acoustical ineasuremenis. the room that contains the noise source or sources.
specific airflow resistance, n—the product of the airflow resistance of a specimen and its area. This is equivalent to the quotient of the air pressure difference across the specimen divided by the linear velocity. measured outside the specimen. of airflow through the specimen.
specific normal acoustic impedance, n—at a surface, the complex quotient obtained when the sound pressure averaged over the surface is divided by the component of the particle velocity normal to the surface. The real and imaginary components of the specific normal acoustic impedance are called, respectively, specific normal acoustic resistance and specific normal acoustic reactance.