disclosed is a device for audibly producing an audio signal including a first speaker , a second speaker , a first housing surrounding the first speaker , a second housing surrounding the second speaker , a curved member having a first curvature and connected to the first housing and the second housing , a receiver for receiving the audio signal , and an energy storage device mounted on the curved member , the energy storage device electrically connected to the receiver and having a second curvature congruent to the first curvature .