MOVI (My Own Voice Interface) is an offline speech recognizer and voice synthesizer that adds voice control functionality to any Arduino project.

What is interesting is their approach to training the on-board acoustic model:

Training: MOVI’s Arduino API sends the training sentences in textual form over the serial connection to the shield. The shield phonetizes sentences using a 2GB dictionary. The phoneme sequences are used to create a temporal model that assigns higher probabilities to phonemes sequences that occurred in the trained sentences than to those that didn’t.

Given that they say they are using open source algorithms which they intend to provide when the shield is released, it will be interesting to see how they've implemented this.