Noise suppression is extremely important in many educational and commercial situations.
In a classroom such as a science lab, echoes need to be around 0.7 os a second but we have seen situations where there is a 2.7 second reverberation time. This makes it absolutely impossible to teach efficiently.
In restaurants and cafes we need a bit of background noise to give a bit of a buzz. However, this needs to be around 76db maximum otherwise you lose customers.
The following article is excellent in explaining the “Cafe Effect”.
We have solutions in the form of ceiling panels and wall tiles which can greatly reduce echoes.