Why do transformers get loud after awhile?

Transformers can become loud over time due to a phenomenon called magnetostriction, where the core material expands and contracts with the magnetic field, producing audible vibrations. Additionally, loose components, aging insulation, and increased load can exacerbate noise levels. Environmental factors, such as temperature changes, can also contribute to increased sound as materials expand or contract. Regular maintenance can help mitigate these issues and reduce noise.