Tinnitus background noise to one that can be heard even over loud external sounds. The specific type of tinnitus called pulsatile tinnitus is characterized by hearing the sounds of one's own pulse or muscle contractions, which is typically a result of sounds that have been created by the movement of muscles near to one's ear, or the sounds are related to blood flow of the neck or face. Due to variations in study designs, data on the course of tinnitus showed few consistent results. Generally the prevalence increased with age in adults, whereas the ratings of annoyance decreased with duration. Persistent
Firefighter lasting affects on the brain. A 2014 report from the National Fallen Firefighters Foundation found that a fire department is three times more likely to experience a suicide in a given year than a line-of-duty death. Mental stress of the job can lead to substance abuse and alcohol abuse as ways of coping with the stress. Another long-term risk factor from firefighting is exposure to high levels of sound, which can cause noise-induced hearing loss (NIHL) and tinnitus. NIHL affects sound frequencies between 3,000 and 6,000 Hertz first, then with more frequent exposure, will spread to more frequencies. Many consonants