When powered on, the localized verbal instructions lead users through the audio user interface. To access recordings, users are guided by audio prompts and respond with key presses. For instance, pressing the right and left arrows navigate through categories (for example, “health”, “agriculture”, “stories”) and once in a category, the up and down arrows rotate through individual messages.
The current version of the Talking Book is 12 cm x 12 cm x 6.5 cm deep and weighs 225 grams without batteries. Devices are typically powered by two, zinc-carbon, size-D batteries, which we have found in rural markets throughout Ghana for $0.35-0.40. These batteries supply 12-15 hours of typical use. Power can be conserved using earphones, but a built-in speaker enables group listening. To improve robustness and affordability, the device has no display. Recordings are stored on an internal microSD memory card, which typically provides 17-70 hours of capacity.