Canadian Science and Sons designed a ceramic iPod (works with any mp3 player) speaker with passive amplification dubbed Phonofone II.
The Phonofone II looks like historic gramophones and also works like them. Without the use of external power or batteries, the Phonofone can boost the audio output of standard earphones to up to 55 decibels (about as loud as laptop speakers). You connect via the earphones to the Phonofone - it is just an acoustic connection.
Three years ago we reported about the Elecom Earhorn. It uses the same horn acoustics in a small portable plastic shape.
The Phonofone II is currently sold as limited prototype design edition (75 pieces, $875 CAD). Phonofone II will be produced as part of a larger serial edition as early as spring 2008.
More details on the Science and Sons site.
How To: Buy a Pokemon Go Plus
Buy Now: Sony PlaysStation VR In Stock Here