Many people suffer from ear noises (tinnitus) or sound sensitivity (hyperacusis). Acute tinnitus symptoms often progress to a chronic form, meaning that the ringing or buzzing in the ear remains permanently audible for many years. If there is also sound sensitivity, those affected perceive the tinnitus as even louder. This guide provides information on the latest knowledge regarding the biological and psychological backgrounds of tinnitus and hyperacusis. It explains how hearing works, what tinnitus and hyperacusis are, and how they can be measured. Additionally, it discusses what can trigger ear noise or sound sensitivity and how they can be maintained. It also outlines what acute treatment for tinnitus looks like and the foundations of professional outpatient treatment.