I've had a buzzing in my ears since I went to a pop concert last night. This sounds like tinnitus, which is a noise often described by sufferers as a buzzing, ringing, or humming. The noise of tinnitus actually comes from within the ear, not outside.
Most people find it worse at night, when the surroundings are quieter.
It's usually older people who are troubled by it when wear and tear, and the degeneration of hair cells in the inner ear that comes with age underlies the problem. However, young people suffer too when these hair cells are damaged by loud noises at nightclubs, concerts, and some hobbies - such as shooting and motor racing, for example. People who work with noisy machinery put themselves at risk, which is why it's important to wear ear-protectors. Trauma to the ear, infection, wax, stress, and some medicines can also be responsible. Coffee, tea, and alcohol can make the noise worse.