When people process information under stress, they commonly experience Mental Noise. When people experience high levels of emotional arousal or mental agitation, it can impair their ability to process information. This phenomenon, known as mental noise, can make it difficult for some people to hear, understand, or remember information, especially when they feel they are at great risk. For example, in an emergency evacuation of a building, some people may not be able to process instructions about what to do, even though they could understand them in non-emergency circumstances.