The sound may be soft or loud, low pitched or high pitched and appear to be coming from one ear or both. Most of the time, it comes on gradually. In some people, the sound causes depression, anxiety, or concentration difficulties.Tinnitus is not a disease but a symptom that can result from a number of underlying causes. One of the most common causes is noise-induced hearing loss. Other causes include: ear infections, disease of the heart or blood vessels, Ménières disease, brain tumors, emotional stress, exposure to certain medications, a previous head injury, and earwax. It is more common in those with depression and anxiety. Society and culture
The ears have been ornamented with jewelry for thousands of years, traditionally by piercing of the earlobe. In ancient and modern cultures, ornaments have been placed to stretch and enlarge the earlobes, allowing for larger plugs to be slid into a large fleshy gap in the lobe. Tearing of the earlobe from the weight of heavy earrings, or from traumatic pull of an earring (for example, by snagging on a sweater), is fairly common.Injury to the ears has been present since Roman times as a method of reprimand or punishment – "In Roman times, when a dispute arose that could not be settled amicably, the injured party cited the name of the person thought to be responsible before the Praetor; if the offender did not appear within the specified time limit, the complainant summoned witnesses to make statements.
Development
During embryogenesis the ear develops as three distinct structures: the inner ear, the middle ear and the outer ear. Each structure originates from a different germ layer: the ectoderm, endoderm and mesenchyme. Inner ear
After implantation, around the second to third week the developing embryo consists of three layers: endoderm, mesoderm and ectoderm. The first part of the ear to develop is the inner ear, which begins to form from the ectoderm around the 22nd day of the embryos development. Specifically, the inner ear derives from two thickenings called otic placodes on either side of the head. Each otic placode recedes below the ectoderm, forms an otic pit and then an otic vesicle. This entire mass will eventually become surrounded by mesenchyme to form the bony labyrinth.Around the 33rd day of development, the vesicles begin to differentiate. Closer to the back of the embryo, they form what will become the utricle and semicircular canals. Closer to the front of the embryo, the vesicles differentiate into a rudimentary saccule, which will eventually become the saccule and cochlea. Part of the saccule will eventually give rise and connect to the cochlear duct. This duct appears approximately during the sixth week and connects to the saccule through the ductus reuniens.As the cochlear ducts mesenchyme begins to differentiate, three cavities are formed: the scala vestibuli, the scala tympani and the scala media. Both the scala vestibuli and the scala tympani contain an extracellular fluid called perilymph. The scala media contains endolymph.