
Acoustics lexicon
Reverberation ("t" time and calculation)
- ... is the significant room acoustic parameter...
- ... is the time that elapses until the sound level in the room has dropped by 60 decibels
- ... can be easily measured
- ... or can be roughly estimated by sighting
Source: W.C. Sabine

Sound attenuation = Sound absorption ("a")
- Room acoustic parameter
- Obstruction of sound propagation by absorption of airborne sound (physical definition).
- The sound is not reflected from the surface, but absorbed
- Unpleasant reverberation is reduced by absorption
- Goal: Change room sound to improve room acoustics, create optimal listening conditions.
Sound insulation
- Building acoustics parameter
- Improve acoustic separation between rooms
Frequency ranges ("Hz")
- Frequency = The frequency of oscillations. Small number of oscillations produce low tones, the more oscillations, the higher the tones.
- Room acoustics: 63 - 8,000 Hz
- Hearing range of the human ear: 16 - 20,000 Hz
- Building acoustics: 100 - 3,150 Hz
Sound pressure level dB (A)
- is a logarithmic quantity for describing the strength of a sound event. Colloquially, sound level usually refers to loudness or noise intensity.
- We perceive a 10 dB increase in level as approximately doubling the volume Examples:
- Kindergartens: approx. 80-85 dB
- quiet conversation 40 - 60 dB
- heavy road traffic 70 - 90 dB
Standards / Guidelines / Recommendations
- DIN 4109: Sound insulation in building construction
- ArbStättV and UVV Noise § 15
Recommendations only:
- DIN 18041: audibility in small to medium-sized rooms
- DIN 18032: Audibility in sports halls - Halls and rooms for sports and multipurpose use
- VDI 2058: Assessment of noise at the workplace taking into account different activities
- VDI 2569: Sound insulation and acoustic design in the office
Evaluation of the sound absorption capacity of materials
- a: Schallabsorptionsgrad: Werte zwischen 0 (vollständige Reflexion) und 1 (vollständige Absorption). Absorption je nach Frequenz unterschiedlich.
- as: Frequency-dependent sound absorption coefficient: absorption values at 18 frequencies between 100Hz -5000Hz
- aw: weighted / weighted sound absorption coefficient: measure of sound absorption capacity: a value between 0 and 1. For complete reflection, a=0, for complete absorption, a=1.