Sound insulation key figures
Sound refers to mechanical vibrations and waves that propagate in the air, in water and in any other medium. These vibrations or waves are perceived by the human ear in the range of 16-16,000 Hertz. Sound propagating through solids is called structure-borne noise, e.g. sound produced by walking is “impact sound”. This structure-borne sound is audible when it is emitted as airborne sound.
Frequency (f) and Hertz (Hz):
The frequency indicates the number of oscillations of the sound wave per second. High, shrill tones have a high frequency (many oscillations in the unit of time), deep, dull tones have a low frequency (few oscillations in the unit of time).
The unit of measurement of the frequency is “Hertz (Hz)”, where 1 Hz means “one oscillation per second”.
is the abbreviation for decibels (1 dB = 1/10 Bel; the Bel was named after Graham Bell, the inventor of the electromagnetic telephone). It is a dimensionless unit of logarithmic physical quantities, which are then called levels. In sound engineering, airborne and structure-borne sound levels are given in dB.
Rated sound reduction index (Rw):
After determining the sound reduction index R for specified frequencies, the weighted sound reduction index Rw is calculated in accordance with DIN EN ISO 717-1. It is expressed in the unit of measure decibel (dB). For this purpose, the R values determined by measurement are compared with reference values according to EN 717-1. The reference curve is shifted vertically parallel to the ordinate in the measurement diagram in accordance with EN 717-1 until the undershoot of the measurement curve is on average no more than 2 dB. In this case, exceedances are not taken into account. The ordinate value of the shifted reference curve at 500 Hz corresponds to the weighted sound reduction index Rw (so-called “single value”).
In order to take into account the different frequency spectra of residential and traffic noise, so-called spectrum adaptation values C and Ctr for the building acoustics range of 100-3150 Hz were introduced in accordance with DIN EN ISO 717-1. They are used to adjust the weighted sound reduction index over a frequency range of 100-3150 Hz. The spectrum adaptation values C100-5000 and Ctr100-5000 additionally take into account the spectrum in the frequency range of 100-5000 Hz. The spectrum adjustment values are product properties that result from the measured sound absorption curve of the glass products, taking into account the relevant noise sources.