 Hearing the shape of a drum

"Hearing the shape of a drum" is a phrase that refers to a famous mathematical problem in the field of spectral geometry. The question it raises is whether it is possible to determine the shape (or geometric properties) of a drum (a two-dimensional object) solely from the sounds it makes when struck. More formally, this involves studying whether two different shapes can have the same set of vibrational frequencies, known as their eigenvalues.