What is a transformer buzz?

A transformer is an essential part of the power grid, responsible for converting high voltage electricity to lower voltage electricity that can be used safely in homes and businesses. It is not uncommon to hear them buzzing or humming as they do their job. Normal transformer noise is a low humming or buzzing sound that is usually constant and not overly loud. This sound is caused by the magnetic field that is produced when electricity flows through the transformer's coils.