A US citizen has complained that cockerel crowing at 49 decibels was not loud enough to constitute a nuisance because the local level was set at 50 decibels. A typical washing machine throbs away at a noise level of around 78 decibels and you have to be exposed to prolonged noise at 90 decibels or higher to risk noise related hearing loss. However, a cockerel in Scotland was threatened with an ASBO as result of anti-social round the clock crowing. This is because the Noise Act (1996) defines noise as an unwanted sound which will be termed a statutory nuisance if it can be deemed serious enough to damage a person's health. This would include sleep loss and any interference with relaxation in a person of "normal sensitivities". So a cockerel is loud but not loud enough to damage hearing but the frequency and unpredictable timing of it's crowing could lead to the birds being deemed a public noise nuisance under current UK laws.
