MRI headphones work by having no wires or drivers near or inside the MRI machine. Instead, the headphones consist of just a cup with a tube extending from them that leads to another room where the drivers are located. This unique design allows sound to be transported along the tube via air, avoiding any magnetic materials that could interfere with the MRI process. Despite the simplicity of this solution, the headphones may sound terrible. The author’s curiosity about how the headphones work was sparked during their MRI, leading to a surprising discovery about the technology behind MRI headphones.
https://tomlingham.com/articles/how-do-mri-headphones-work/