An interior with many hard materials such as concrete, glass or a screed floor causes poor acoustics. Sound waves that hit a hard surface are reflected.
These reflections not only cause a direct sound, but also an indirect sound, to enter the room. The indirect sound is then perceived as reverberation. Reverberation in a religious building can be enjoyable, but in an office or classroom, it is rather undesirable.
High reverberation makes it more difficult to be able to understand each other. This requires extra effort and concentration. As a result, the brain becomes fatigued more quickly. At work, this reduces productivity and increases stress levels.