Sound insulation

Sound protection is an important criteria for the quality of residential and work spaces inside buildings. The minimum requirements for buildings are specified in the corresponding national standards.

We recommend that the builder and the contractor should agree on the required sound protection even for single family houses. Furthermore, we recommend to follow higher requirements when it comes to sound protection for ceilings. In addition to direct sound transmission through the construction component, the transmission via flanking components must also be taken into account during planning and execution.

The planning and execution of connections and openings are of particular importance, as the renovation of sound insulation deficiencies is usually difficult and costly.

Specific terminology in sound protection

• Sound
  Mechanical vibration that propagates in elastic media through the vibration of the mass particles around their rest position, which creates compaction and dilution within the medium.
   
• Airborne sound
  Sound that propagates through the air, e.g., music from a radio.
   
• Structure-borne sound
  Sound that propagates in solid materials, e.g., from a drilling machine.
   
• Impact sound
  Sound that arises when walking on floors and stairs as structure-borne sound, and is partially radiated as airborne sound in neighbouring rooms.
   
• Sound insulation index R [dB]
  Sound insulation index for a partitioning component. Sound transmission occurs exclusively via the partitioning component. The higher the value of R, the better the airborne sound insulation of a component.
   
• Sound insulation index R’ [dB]
  Sound insulation index analogous to R, but sound transmission both via the partitioning component and the flanking components.
   
• Calculation value of the evaluated sound insulation index R’_w,R [dB]
  Calculation value of the evaluated sound insulation index depending on the mass per unit area of flanking components.
   
• Check value of the evaluated sound insulation index R’_w,P [dB]
  This value was determined in the laboratory under ideal conditions. The conversion R_’w,R in R_’wP includes an allowance of 2 dB for walls and ceilings.
   
• Evaluated standard impact-noise level L’_n,w [dB]
  Identification of the impact-noise insulation of a component. Sound transmission both via the partitioning component and the flanking components. The lower the L_’n,w , the better the impact-noise insulation.
   
• Evaluated sound insulation index R’_w [dB]
  Calculation of a measured sound insulation index curve for a component with an evaluation curve that takes into account the frequency range of human ear sensitivity.
   
• Evaluated standard sound level difference D_nT,w [dB]
  designates the airborne sound insulation between two rooms taking into account the reverberation time in the receiving room and the reference reverberation time according to 717-1.

Link between D_n,T,w and R’_w:
R’_w = Dn,T,_w + C [dB]                             C = - 10 log (V) + 10 log S + 10 log (T₀ / 0.163)

C: Level correction
T₀: Reference reverberation time in [s]
V: Volume of the receiving room in m³
     V ≤ 100 m³ à T₀ = 0.5 s
     V > 100 m³ ≤ 2500 m³ à T₀ = 1.0 s
     V > 2500 m³ _ T_ = 2.5 s
S: Common area of the partitioning component in m²