A company called Apollo Japan has developed the so-called Speakun [JP], a pen-shaped device that’s able to read invisible codes printed on paper and then plays back pre-recorded sounds. Users first have to scan special, dot-shaped codes (0.04mm in diameter) that are associated with pictures or texts on a piece of paper.
The Speakun then plays back audio (comments, messages, etc.) that belongs to said content and is stored on microSD cards. Needless to say, this only works with content that contains Speakun-compatible codes.
Apollo Japan plans to start selling the Speakun for $100 in Japan in September. The company sees its invention being used in photo albums, greeting cards, manuals or instruction materials. The sales target for the first year is 10,000 units.