A headphone system includes a first audio speaker assembly and a second audio speaker assembly, a connecting body extending between the first and second audio speaker assemblies, and a light-diffusing fiber coupled with the connecting body, the light-diffusing fiber having a glass core and a cladding. At least one of the glass core and a core-cladding interface includes a plurality of light scattering structures. A light source is optically coupled to the light-diffusing fiber and configured to emit light into the light-diffusing fiber. The light scattering structures are configured to scatter the emitted light and output the emitted light at least partially along a sidewall of the light-diffusing fiber.