Sound reflection

In acoustics sound reflection is the ‘bouncing back’ of sound. Level, non-sound-absorbent surfaces reflect sound waves well. The echo threshold plays an important role in the recognition of these sound reflections. Depending on the arrangement and number of the reflecting surfaces and how the sound is reflected, the reflected sound is heard differently. As:

  •  Echoes (wall at a relatively large distance)

  •  Flutter echo (two parallel reflecting walls)

  •  Reverberation (large rooms having hard walls, e.g. as in churches)

  •  High three-dimensionality (acoustic feeling of space, e.g. as in concert halls)

  •  ‘Dry’ sound (in rooms having surfaces that reflect little of the sound)


The following are important for the acoustic impression:


  •  Proportion of direct sound at the overall sound level

  •  Time delay and direction of ‘early reflections’, as well as their share of the total sound level

  •  Deployment delay and spatial distribution of the reverberation, as well as its share of the overall sound level and its temporal progression (reverberation time)

The reverberation time and/or the flutter effect can be significantly reduced in rooms by means of light blankets made of woven fabrics. With double-layered systems such as Lightframe, the acoustic effectiveness can be further intensified.


Direct sound, ‘early reflections’ and reverberation