A number of factors must be taken into consideration, such as time the noise occurs, duration of the noise, necessity for the noise, noise levels, nature of the locality etc.
Rhaid rhoi ystyriaeth i nifer o ffactorau, megis pryd mae'r sŵn yn digwydd, hyd y sŵn, angenrheidrwydd y sŵn, lefelau sŵn, natur yr ardal ac ati.