Zach Fredin made a cochlea prototype  – a human ear response for NeuroBytes neuron simulator system.

This video shows the prototype in action.

NeuroBytes are hands-on electronic neuron simulators that allow individuals to learn about the brain while physically building their own neural circuits, synapse by synapse.

Neuro Tinker has a Kickstarter in process for their NeuroBytes system.  The system is made up of modular neuron simulators that allow the user to build and simulate their own electronic brain.

NeuroBytes are fully open sourced,  All source files – schematics, PCB Layout, firmware, etc – are available and shared freely.