Liu and associates studied how various sounds influence mental recovery from stress. They “compar[ed] a silent environment (control group) with three experimental groups exposed to flowing water sound, birdsong, and wind sounds. The investigation entailed the assessment of subjective assessments and EEG signals . . . the [perceived restorativeness] scores for the sounds of flowing water and birdsong were superior to those of the silent environment. The EEG results revealed that EEG-α activity was more pronounced in response to natural…