In some shared or public spaces, noise levels have a direct impact on safety and security. Excessive noise can negatively affect speech intelligibility, which is a problem when it comes to understanding the content of public announcements made over the public address or voice alarm Systems in schools and train stations, for example. Poor speech intelligibility is particularly detrimental in public emergencies, where announcements contain instructions intended to lead people to safety.

Noise exposure can even lead to a higher occurrence of human errors and inappropriate aggressive social behaviour among predisposed individuals. It has been shown that ‘helping behaviour’ declines in environments where noise levels rise above 80 dBA. It has also been shown that schoolchildren exposed to high levels of noise may be more susceptible to helplessness.

A well designed acoustic environment supports public safety and security by enhancing speech intelligibility and creating a less agitating and more peaceful soundscape where people can think clearly and maintain awareness of their surroundings..